388 results on '"Bernier, N."'
Search Results
2. The soil-conscious forestry and the forbidden apple
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Zanella A, Bernier N, Zampedri R, Fusaro S, Mei G, André J, Ponge J-F, and Giannini R
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Anthropocene ,Adam and Eve ,Forest Soil ,Humus ,Soil-conscious Forestry ,Envers Forest ,Forestry ,SD1-669.5 - Abstract
In this article, we propose a silvicultural approach that takes soil health into account. Using a biblical metaphor, the first chapter highlights the forest’s critical role in the planet’s future, emphasizing that forest biodiversity is essential for sustaining a planet inhabited by complex life forms like humans. The second chapter focuses to the soil, explaining how the biological dynamics of the soil are interconnected with the forest cycle, demonstrating that vegetation and soil form a continuous, co-evolving system. The third chapter explores the possibility of extending the forest cycle to restore soil functionality, illustrating how the recycling of the forest’s biological past facilitates the emergence of a new, evolving soil-vegetation system. Examples of forest management practices in France, Italy, and Switzerland are presented, including graphs and mathematical models depicting the evolution of organic carbon in the soil and the distribution of tree stems by diameter, age, and stature. The description of uneven-aged Swiss forests, featuring fir and beech, is sourced from the Helvetica Pro-Silva website.
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- 2024
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3. Decay Spectroscopy of $^{160}$Eu: Quasiparticle Configurations of Excited States and Structure of $K^\pi$=$4^+$ Band-heads in $^{160}$Gd
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Yates, D., Kruecken, R., Dillmann, I., Garrett, P. E., Olaizola, B., Vedia, V., Ali, F. A., Andreoiu, C., Ashfield, W., Ball, G. C., Beadle, Z., Bernier, N., Bhattacharjee, S. S., Bidaman, H., Bildstein, V., Bishop, D., Bowry, M., Burbadge, C., Caballero-Folch, R., Chaney, D. Z., Cross, D. C., Varela, A. Diaz, Dunlop, M. R., Dunlop, R., Evitts, L. J., Garcia, F. H., Garnsworthy, A. B., Georges, S., Gillespie, S. A., Hackman, G., Henderson, J., Jigmeddorj, S., Lassen, J., Li, R., Luna, B. K., MacLean, A. D., Natzke, C. R., Petrache, C. M., Radich, A. J., Rajabali, M. M., Regan, P. H., Saito, Y., Smallcombe, J., Smith, J. K., Spieker, M., Svensson, C. E., Whitmore, A. Teigelhoefer K., and Zidar, T.
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Nuclear Experiment - Abstract
\noindent \textbf{Background:} Detailed spectroscopy of neutron-rich, heavy, deformed nuclei is of broad interest for nuclear astrophysics and nuclear structure. Nuclei in the r-process path and following freeze-out region impact the resulting r-process abundance distribution, and the structure of nuclei midshell in both proton and neutron number helps to understand the evolution of subshell gaps and large deformation in these nuclei. \noindent \textbf{Purpose:} To improve the understanding of the nuclear structure of $^{160}$Gd, specifically the $K^\pi$=$4^+$ bands, as well as study the $\beta$-decay of $^{160}$Eu into $^{160}$Gd. \noindent \textbf{Methods:} High-statistics decay spectroscopy of $^{160}$Gd resulting from the $\beta$-decay of $^{160}$Eu was collected using the GRIFFIN spectrometer at the TRIUMF-ISAC facility. \noindent \textbf{Results:} Two new excited states and ten new transitions were observed in $^{160}$Gd. The $\beta$-decaying half-lives of the low- and high-spin isomer in $^{160}$Eu were determined, and the low-spin state's half-life was measured to be $t_{1/2}=26.0(8)$~s, $\sim$16\% shorter than previous measurements. Lifetimes of the two $K^\pi$=$4^+$ band-heads in $^{160}$Gd were measured for the first time, as well as $\gamma$-$\gamma$ angular correlations and mixing ratios of intense transitions out of those band-heads. \noindent \textbf{Conclusions:} Lifetimes and mixing ratios suggest that the hexadecapole phonon model of the $K^\pi$=$4^+$ band-heads in $^{160}$Gd is preferred over a simple two-state strong mixing scenario, although further theoretical calculations are needed to fully understand these states. Additionally, the 1999.0 keV state in $^{160}$Gd heavily populated in $\beta$-decay is shown to have positive parity, which raises questions regarding the structure of the high-spin $\beta$-decaying state in $^{160}$Eu.
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- 2023
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4. Spin-orbit readout using thin films of topological insulator Sb2Te3 deposited by industrial magnetron sputtering
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Teresi, S., Sebe, N., Frottier, T., Patterson, J., Kandazoglou, A., Noël, P., Sgarro, P., Térébénec, D., Bernier, N., Hippert, F., Attané, J. -P., Vila, L., Noé, P., and Cosset-Chéneau, M.
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Condensed Matter - Mesoscale and Nanoscale Physics ,Condensed Matter - Materials Science - Abstract
Driving a spin-logic circuit requires the production of a large output signal by spin-charge interconversion in spin-orbit readout devices. This should be possible by using topological insulators, which are known for their high spin-charge interconversion efficiency. However, high-quality topological insulators have so far only been obtained on a small scale, or with large scale deposition techniques which are not compatible with conventional industrial deposition processes. The nanopatterning and electrical spin injection into these materials has also proven difficult due to their fragile structure and low spin conductance. We present the fabrication of a spin-orbit readout device from the topological insulator Sb2Te3 deposited by large-scale industrial magnetron sputtering on SiO2. Despite a modification of the Sb2Te3 layer structural properties during the device nanofabrication, we measured a sizeable output voltage that can be unambiguously ascribed to a spin-charge interconversion process.
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- 2023
5. Decay spectroscopy of Eu160: Quasiparticle configurations of excited states and structure of Kπ=4+ bandheads in Gd160
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Yates, D, Krücken, R, Dillmann, I, Garrett, PE, Olaizola, B, Vedia, V, Ali, FA, Andreoiu, C, Ashfield, W, Ball, GC, Beadle, Z, Bernier, N, Bhattacharjee, SS, Bidaman, H, Bildstein, V, Bishop, D, Bowry, M, Burbadge, C, Caballero-Folch, R, Chaney, DZ, Cross, DC, Varela, A Diaz, Dunlop, MR, Dunlop, R, Evitts, LJ, Garcia, FH, Garnsworthy, AB, Georges, S, Gillespie, SA, Hackman, G, Henderson, J, Jigmeddorj, B, Lassen, J, Li, R, Luna, BK, MacLean, AD, Natzke, CR, Petrache, CM, Radich, AJ, Rajabali, MM, Regan, PH, Saito, Y, Smallcombe, J, Smith, JK, Spieker, M, Svensson, CE, Teigelhöfer, A, Whitmore, K, and Zidar, T
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Nuclear and Plasma Physics ,Synchrotrons and Accelerators ,Physical Sciences ,Nuclear and plasma physics - Abstract
Background: Detailed spectroscopy of neutron-rich, heavy, deformed nuclei is of broad interest for nuclear astrophysics and nuclear structure. Nuclei in the r-process path and following freeze-out region impact the resulting r-process abundance distribution, and the structure of nuclei midshell in both proton and neutron number helps to understand the evolution of subshell gaps and large deformation in these nuclei. Purpose: We aim to improve the understanding of the nuclear structure of Gd160, specifically the Kπ=4+ bands, as well as study the β decay of Eu160 into Gd160. Methods: High-statistics decay spectroscopy of Gd160 resulting from the β-decay of Eu160 was collected using the GRIFFIN spectrometer at the TRIUMF-ISAC facility. Results: Two new excited states and ten new transitions were observed in Gd160. The β-decaying half-lives of the low- and high-spin isomers in Eu160 were determined, and the low-spin state's half-life was measured to be t1/2=26.0(8) s, ≈16% shorter than previous measurements. Lifetimes of the two Kπ=4+ bandheads in Gd160 were measured for the first time, as well as γ-γ angular correlations and mixing ratios of intense transitions out of those bandheads. Conclusions: Lifetimes and mixing ratios suggest that the hexadecapole phonon model of the Kπ=4+ bandheads in Gd160 is preferred over a simple two-state strong mixing scenario, although further theoretical calculations are needed to fully understand these states. Additionally, the 1999.0-keV state in Gd160 heavily populated in β decay is shown to have positive parity, which raises questions regarding the structure of the high-spin β-decaying state in Eu160.
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- 2023
6. Single neutron transfer on 23Ne and its relevance forthepathway ofnucleosynthesis in astrophysical X-ray bursts
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Lotay, G., Henderson, J., Catford, W. N., Ali, F. A., Berean, J., Bernier, N., Bhattacharjee, S. S., Bowry, M., Caballero-Folch, R., Davids, B., Drake, T. E., Garnsworthy, A. B., GhaziMoradi, F., Gillespie, S. A., Greaves, B., Hackman, G., Hallam, S., Hymers, D., Kasanda, E., Levy, D., Luna, B. K., Mathews, A., Meisel, Z., Moukaddam, M., Muecher, D., Olaizola, B., Orr, N. A., Patel, H. P., Rajabali, M. M., Saito, Y., Smallcombe, J., Spencer, M., Svensson, C. E., Whitmore, K., and Williams, M.
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Nuclear Experiment - Abstract
We present new experimental measurements of resonance strengths in the astrophysical 23Al(p, {\gamma})24Si reaction, constraining the pathway of nucleosynthesis beyond 22Mg in X-ray burster scenarios. Specifically, we have performed the first measurement of the (d, p) reaction using a radioactive beam of 23Ne to explore levels in 24Ne, the mirror analog of 24Si. Four strong single-particle states were observed and corresponding neutron spectroscopic factors were extracted with a precision of {\sim}20{\%}. Using these spectroscopic factors, together with mirror state identifications, we have reduced uncertainties in the strength of the key {\ell} = 0 resonance at Er= 157 keV, in the astrophysical 23Al(p, {\gamma}) reaction, by a factor of 4. Our results show that the 22Mg(p, {\gamma})23Al(p, {\gamma}) pathway dominates over the competing 22Mg({\alpha}, p) reaction in all but the most energetic X-ray burster events (T>0.85GK), significantly affecting energy production and the preservation of hydrogen fuel., Comment: 5 pages, 3 figures
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- 2022
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7. Characterization of electroless nickel-phosphorus plating for ultracold-neutron storage
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Akatsuka, H., Andalib, T., Bell, B., Berean-Dutcher, J., Bernier, N., Bidinosti, C. P., Cude-Woods, C., Currie, S. A., Davis, C. A., Franke, B., Gaur, R., Giampa, P., Hansen-Romu, S., Hassan, M. T., Hatanaka, K., Higuchi, T., Gibson, C., Ichikawa, G., Ide, I., Imajo, S., Ito, T. M., Jamieson, B., Kawasaki, S., Kitaguchi, M., Klassen, W., Korkmaz, E., Kuchler, F., Lang, M., Lavvaf, M., Lindner, T., Makela, M., Mammei, J., Mammei, R., Martin, J. W., Matsumiya, R., Miller, E., Mishima, K., Momose, T., Morawetz, S., Morris, C. L., Ong, H. J., O'Shaughnessy, C. M., Pereira-Wilson, M., Picker, R., Piermaier, F., Pierre, E., Schreyer, W., Sidhu, S., Stang, D., Tiepo, V., Vanbergen, S., Wang, R., Wong, D., and Yamamoto, N.
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Nuclear Experiment - Abstract
Electroless nickel plating is an established industrial process that provides a robust and relatively low-cost coating suitable for transporting and storing ultracold neutrons (UCN). Using roughness measurements and UCN-storage experiments we characterized UCN guides made from polished aluminum or stainless-steel tubes plated by several vendors. All electroless nickel platings were similarly suited for UCN storage with an average loss probability per wall bounce of $2.8\cdot10^{-4}$ to $4.1\cdot10^{-4}$ for energies between 90 neV and 190 neV, or a ratio of imaginary to real Fermi potential $\eta$ of $1.7\cdot10^{-4}$ to $3.3\cdot10^{-4}$. Measurements at different elevations indicate that the energy dependence of UCN losses is well described by the imaginary Fermi potential. Some special considerations are required to avoid an increase in surface roughness during the plating process and hence a reduction in UCN transmission. Increased roughness had only a minor impact on storage properties. Based on these findings we chose a vendor to plate the UCN-production vessel that will contain the superfluid-helium converter for the new TRIUMF UltraCold Advanced Neutron (TUCAN) source, achieving acceptable UCN-storage properties with ${\eta=3.5(5)\cdot10^{-4}}$., Comment: 8 pages, 7 figures
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- 2022
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8. High-precision half-life determination of $^{14}$O via direct $\beta$ counting
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Sharma, S., Grinyer, G. F., Ball, G. C., Leslie, J. R., Svensson, C. E., Ali, F. A., Andreoiu, C., Bernier, N., Bhattacharjee, S. S., Bildstein, V., Burbadge, C., Caballero-Folch, R., Coleman, R., Varela, A. Diaz, Dunlop, M. R., Dunlop, R., Garnsworthy, A. B., Fuakye, E. Gyabeng, Huber, G. M., Jigmeddorj, B., Kapoor, K., Laffoley, A. T., Leach, K. G., Long, J., MacLean, A. D., Natzke, C. R., Olaizola, B., Radich, A. J., Saei, N., Smallcombe, J. T., Talebitaher, A., Whitmore, K., and Zidar, T.
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Nuclear Experiment - Abstract
The half-life of the superallowed Fermi $\beta^+$ emitter $^{14}$O was determined to high precision via a direct $\beta$ counting experiment performed at the Isotope Separator and Accelerator (ISAC) facility at TRIUMF. The result, $T_{1/2}$($^{14}$O) = 70619.2(76) ms, is consistent with, but is more precise than, the world average obtained from 11 previous measurements. Combining the $^{14}$O half-life deduced in the present work with the previous most precise measurements of this quantity leads to a reduction in the overall uncertainty, by nearly a factor of 2. The new world average is $T_{1/2}$($^{14}$O) = 70619.6(63) ms with a reduced $\chi^2$ value of 0.87 obtained from 8 degrees of freedom., Comment: 8 pages, 6 figures, accepted for publication in the European Physical Journal A
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- 2022
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9. Ex-situ n-type doped carrier-injection layers in direct bandgap GeSn LEDs
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Casiez, L., Cardoux, C., Acosta Alba, P., Bernier, N., Richy, J., Pauc, N., Calvo, V., Coudurier, N., Rodriguez, P., Concepción, O., Buca, D., Frauenrath, M., Hartmann, J.M., Chelnokov, A., and Reboud, V.
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- 2024
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10. Spectroscopic studies of neutron-rich $^{129}$In and its $\beta$-decay daughter, $^{129}$Sn, using the GRIFFIN spectrometer
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Garcia, F. H., Andreoiu, C., Ball, G. C., Bernier, N., Bidaman, H., Bildstein, V., Bowry, M., Cross, D. S., Dunlop, M. R., Dunlop, R., Garnsworthy, A. B., Garrett, P. E., Henderson, J., Measures, J., Olaizola, B., Ortner, K., Park, J., Petrache, C. M., Pore, J. L., Raymond, K., Smith, J. K., Southall, D., Svensson, C. E., Ticu, M., Turko, J., Whitmore, K., and Zidar, T.
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Nuclear Experiment - Abstract
The $\beta$-decay of neutron-rich $^{129}$In into $^{129}$Sn was studied using the GRIFFIN spectrometer at the ISAC facility at TRIUMF. The study observed the half-lives of the ground state and each of the $\beta$-decaying isomers. The level scheme of $^{129}$Sn has been expanded with thirty-one new $\gamma$-ray transitions and nine new excited levels, leading to a re-evaluation of the $\beta$-branching ratios and level spin assignments. The observation of the $\beta$-decay of the (29/2$^{+}$) 1911-keV isomeric state in $^{129}$In is reported for the first time, with a branching ratio of 2.0(5)$\%$.
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- 2021
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11. Absence of Low-Energy Shape Coexistence in $^{80}$Ge: The Nonobservation of a Proposed Excited 0$_2^+$ Level at 639 keV
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Garcia, F. H., Andreoiu, C., Ball, G. C., Bell, A., Garnsworthy, A. B., Nowacki, F., Petrache, C. M., Poves, A., Whitmore, K., Ali, F. A., Bernier, N., Bhattacharjee, S. S., Bowry, M., Coleman, R. J., Dillmann, I., Djianto, I., Forney, A. M., Gascoine, M., Hackman, G., Leach, K. G., Murphy, A. N., Natzke, C. R., Olaizola, B., Ortner, K., Peters, E. E., Rajabali, M. M., Raymond, K., Svensson, C. E., Umashankar, R., Williams, J., and Yates, D.
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Nuclear Experiment - Abstract
The $^{80}$Ge structure was investigated in a high-statistics $\beta$-decay experiment of $^{80}$Ga using the GRIFFIN spectrometer at TRIUMF-ISAC through $\gamma$, $\beta$-$e$, $e$-$\gamma$ and $\gamma$-$\gamma$ spectroscopy. No evidence was found for the recently reported 0$_2^{+}$ 639-keV level suggested as evidence for low-energy shape coexistence in $^{80}$Ge. Large-scale shell model calculations performed in $^{78,80,82}$Ge place the $0^{+}_{2}$ level in $^{80}$Ge at 2\,MeV. The new experimental evidence combined with shell model predictions indicate that low-energy shape coexistence is not present in $^{80}$Ge.
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- 2020
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12. Decay Spectroscopy of $^{129}$Cd
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Saito, Y., Dillmann, I., Krücken, R., Bernier, N., Ball, G. C., Bowry, M., Andreoiu, C., Bidaman, H., Bildstein, V., Boubel, P., Burbadge, C., Caballero-Folch, R., Dunlop, M. R., Dunlop, R., Evitts, L. J., Garcia, F. H., Garnsworthy, A. B., Garrett, P. E., Grawe, H., Hackman, G., Hallam, S., Henderson, J., Ilyushkin, S., Jungclaus, A., Kisliuk, D., Lassen, J., Li, R., MacConnachie, E., MacLean, A. D., McGee, E., Moukaddam, M., Olaizola, B., Padilla-Rodal, E., Park, J., Paetkau, O., Petrache, C. M., Pore, J. L., Radich, A. J., Ruotsalainen, P., Smallcombe, J., Smith, J. K., Svensson, C. E., Teigelhöfer, A., Turko, J., and Zidar, T.
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Nuclear Experiment ,Nuclear Theory - Abstract
Excited states of $^{129}$In populated following the $\beta$-decay of $^{129}$Cd were experimentally studied with the GRIFFIN spectrometer at the ISAC facility of TRIUMF, Canada. A 480-MeV proton beam was impinged on a uranium carbide target and $^{129}$Cd was extracted using the Ion Guide Laser Ion Source (IG-LIS). $\beta$- and $\gamma$-rays following the decay of $^{129}$Cd were detected with the GRIFFIN spectrometer comprising the plastic scintillator SCEPTAR and 16 high-purity germanium (HPGe) clover-type detectors. %, along with the $\beta$-particles were detected with SCEPTAR. From the $\beta$-$\gamma$-$\gamma$ coincidence analysis, 32 new transitions and 7 new excited states were established, expanding the previously known level scheme of $^{129}$In. The $\log ft$ values deduced from the $\beta$-feeding intensities suggest that some of the high-lying states were populated by the $\nu 0 g_{7/2} \rightarrow \pi 0 g_{9/2}$ allowed Gamow-Teller (GT) transition, which indicates that the allowed GT transition is more dominant in the $^{129}$Cd decay than previously reported. Observation of fragmented Gamow-Teller strengths is consistent with theoretical calculations., Comment: 13 pages, 9 figures, to be published in Physical Review C
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- 2020
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13. $\beta$ Decay of $^{132}$In and Spectroscopy of $^{132}$Sn and $^{131}$Sb with the GRIFFIN Spectrometer
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Whitmore, K., Andreoiu, C., Garcia, F. H., Ortner, K., Holt, J. D., Miyagi, T., Ball, G. C., Bernier, N., Bidaman, H., Bildstein, V., Bowry, M., Cross, D. S., Dunlop, M. R., Dunlop, R., Garnsworthy, A. B., Garrett, P. E., Henderson, J., Measures, J., Olaizola, B., Park, J., Petrache, C. M., Pore, J. L., Smith, J. K., Southall, D., Svensson, C. E., Ticu, M., Turko, J., and Zidar, T.
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Nuclear Experiment - Abstract
Spectroscopy of doubly magic $^{132}_{50}$Sn$_{82}$ has been performed with the GRIFFIN spectrometer at TRIUMF-ISAC following the $\beta$ decay of $^{132}_{49}$In$_{83}$. The analysis has allowed for the placement of a total of 70 transitions and 29 excited states in $^{132}$Sn. Detailed spectroscopy has also been performed on $^{131}$Sb, resulting from the $\beta$ decay of $^{131}$Sn, produced from the $\beta$-delayed neutron decay of $^{132}$In. Measurement of $\gamma$-rays in both $^{131}$Sn and $^{131}$Sb has led to the determination of the $\beta$-delayed neutron emission probability, $P_{n}$, from $^{132}$In. This is the first time the $P_{n}$ has been measured for this nucleus using $\gamma$ spectroscopy, and the new value of 12.3(4)% is consistent with the most recent $\beta-n$ counting experiment. Additionally, $\gamma$-$\gamma$ angular correlations have been performed in $^{132}$Sn, supporting the spin assignments of several excited states. Novel ab initio calculations are presented which describe several of the excited states, and these are compared to the experimental spectrum., Comment: 14 pages, 7 figures, to be published in Physical Review C
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- 2020
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14. Collective 2p-2h intruder states in $^{118}$Sn studied via $\beta$-decay of $^{118}$In using GRIFFIN
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Ortner, K., Andreoiu, C., Spieker, M., Ball, G. C., Bernier, N., Bidaman, H., Bildstein, V., Bowry, M., Cross, D. S., Dunlop, M. R., Dunlop, R., Garcia, F. H., Garnsworthy, A. B., Garrett, P. E., Henderson, J., Measures, J., Olaizola, B., Park, J., Petrache, C. M., Pore, J. L., Raymond, K., Smith, J. K., Southall, D., Svensson, C. E., Ticu, M., Turko, J., Whitmore, K., and Zidar, T.
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Nuclear Experiment - Abstract
The low-lying structure of semi-magic $^{118}$Sn has been investigated through the $\beta$-decay of $^{118}$In ($T_{1/2}=4.45$ min) to study shape coexistence via the reduced transition probabilities of states in the 2p-2h proton intruder band. This high-statistics study was carried out at TRIUMF-ISAC with the GRIFFIN spectrometer. In total, 99 transitions have been placed in the level scheme with 43 being newly observed. Three low-lying $\gamma$-ray transitions with energies near 285 keV have been resolved from which the 2$^+_{\mathrm{intr.}} \rightarrow 0^+_{\mathrm{intr.}}$ 284.52-keV transition was determined to have half of the previous branching fraction leading to a $B(E2;2^+_2\rightarrow 0^+_2)$ of 21(4) W.u. compared to 39(7) W.u. from the previous measurement. Calculations using $sd$ IBM-2 with mixing have also been made to compare the experimental $B(E2)$ values to the theoretical values and to make comparisons to the $^{114,116}$Sn isotopes previously studied using the same theoretical model.
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- 2020
15. Coulomb excitation of the $\left|T_z\right|=\frac{1}{2}$, $A=23$ mirror pair
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Henderson, J., Hackman, G., Ruotsalainen, P., Holt, J. D., Stroberg, S. R., Andreoiu, C., Ball, G. C., Bernier, N., Bowry, M., Caballero-Folch, R., Cruz, S., Varela, A. Diaz, Evitts, L. J., Frederick, R., Garnsworthy, A. B., Holl, M., Lassen, J., Measures, J., Olaizola, B., O'Sullivan, E., Paetkau, O., Park, J., Smallcombe, J., Svensson, C. E., Whitmore, K., and Wu, C. Y.
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Nuclear Experiment ,Nuclear Theory - Abstract
Background: Electric-quadrupole ($E2$) strengths relate to the underlying quadrupole deformation of a nucleus and present a challenge for many nuclear theories. Mirror nuclei in the vicinity of the line of $N=Z$ represent a convenient laboratory for testing deficiencies in such models, making use of the isospin-symmetry of the systems. Purpose: Uncertainties associated with literature $E2$ strengths in \textsuperscript{23}Mg are some of the largest in $T_z=\left|\frac{1}{2}\right|$ nuclei in the $sd$-shell. The purpose of the present work is to improve the precision with which these values are known, to enable better comparison with theoretical models. Methods: Coulomb-excitation measurements of $^{23}$Mg and $^{23}$Na were performed at the TRIUMF-ISAC facility using the TIGRESS spectrometer. They were used to determine the $E2$ matrix elements of mixed $E2$/$M1$ transitions. Results: Reduced $E2$ transition strengths, $B(E2)$, were extracted for \textsuperscript{23}Mg and \textsuperscript{23}Na. Their precision was improved by factors of approximately six for both isotopes, while agreeing within uncertainties with previous measurements. Conclusions: A comparison was made with both shell-model and {\it ab initio} valence-space in-medium similarity renormalization group calculations. Valence-space in-medium similarity-renormalization-group calculations were found to underpredict the absolute $E2$ strength - in agreement with previous studies.
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- 2020
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16. Nanosecond laser annealing of pseudomorphic GeSn layers: Impact of Sn content
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Frauenrath, M., Acosta Alba, P., Concepción, O., Bae, J.-H., Gauthier, N., Nolot, E., Veillerot, M., Bernier, N., Buca, D., and Hartmann, J.-M.
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- 2023
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17. Shape coexistence in the neutron-deficient lead region: A systematic study of lifetimes in the even-even $^{188-200}$Hg with GRIFFIN
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Olaizola, B., Garnsworthy, A. B., Ball, G. C., Bernier, N., Bowry, M., Caballero-Folch, R., Dillmann, I., Georges, S., Hackman, G., Smallcombe, J., Smith, J. K., Southall, D., Timakova, E., Umashankar, R., Ali, F. A., Bidaman, H., Bildstein, V., Burbadge, C., Varela, A. Diaz, Dunlop, R. A., Dunlop, M., Garrett, P. E., Hadina, B., Jigmeddorj, B., Kisliuk, D., Laffoley, A., MacLean, A., Muecher, D., Radich, A., Rand, E. T., Svensson, C. E., Turko, J., Zidar, T., Andreoiu, C., Garcia, F., Pore, J. L., Rizwan, U., Starosta, K., Voss, P., and Williams, J.
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Nuclear Experiment - Abstract
Lifetimes of $2^+_1$ and $4^+_1$ states, as well as some negative-parity and non-yrast states, in $^{188-200}$Hg were measured using $\gamma-\gamma$ electronic fast timing techniques with the LaBr$_3$(Ce) detector array of the GRIFFIN spectrometer. The excited states were populated in the $\epsilon/\beta^+$-decay of $J^\pi =7^+/2^-$ $^{188-200}$Tl produced at the TRIUMF-ISAC facility. The deduced B(E2) values are compared to different interacting boson model predictions. The precision achieved in this work over previous ones allows for a meaningful comparison with the different theoretical models of these transitional Hg isotopes, which confirms the onset of state mixing in $^{190}$Hg.
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- 2019
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18. Direct observation of proton emission in 11Be
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Ayyad, Y., Olaizola, B., Mittig, W., Potel, G., Zelevinsky, V., Horoi, M., Beceiro-Novo, S., Alcorta, M., Andreoiu, C., Ahn, T., Anholm, M., Atar, L., Babu, A., Bazin, D., Bernier, N., Bhattacharjee, S. S., Bowry, M., Caballero-Folch, R., Cortesi, M., Dalitz, C., Dunling, E., Garnsworthy, A. B., Holl, M., Kootte, B., Leach, K. G., Randhawa, J. S., Saito, Y., Santamaria, C., Šiuryte, P., Svensson, C. E., Umashankar, R., Watwood, N., and Yates, D.
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Nuclear Experiment - Abstract
The elusive $\beta^-\text{p}^+$ decay was observed in $^{11}$Be by directly measuring the emitted protons and their energy distribution for the first time with the prototype Active Target Time Projection Chamber (pAT-TPC) in an experiment performed at ISAC-TRIUMF. The measured $\beta^-\text{p}^+$ branching ratio is orders of magnitude larger than any previous theoretical model predicted. This can be explained by the presence of a narrow resonance in $^{11}$B above the proton separation energy.
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- 2019
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19. Shell evolution approaching the N=20 island of inversion: Structure of 29Mg
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Matta, A., Catford, W. N., Orr, N. A., Henderson, J., Ruotsalainen, P., Hackman, G., Garnsworthy, A. B., Delaunay, F., Wilkinson, R., Lotay, G., Tsunoda, Naofumi, Otsuka, Takaharu, Knapton, A. J., Ball, G. C., Bernier, N., Burbadge, C., Chester, A., Cross, D. S., Cruz, S., Diget, C. Aa., Domingo, T., Drake, T. E., Evitts, L. J., Garcia, F. H., Hallam, S., MacConnachie, E., Moukaddam, M., Muecher, D., Padilla-Rodal, E., Paetkau, O., Park, J., Pore, J. L., Rizwan, U., Smallcombe, J., Smith, J. K., Starosta, K., Svensson, C. E., Williams, J., and Williams, M.
- Subjects
Nuclear Experiment - Abstract
The "Island of Inversion" for neutron-rich nuclei in the vicinity of N=20 has become the testing ground par excellence for our understanding and modelling of shell evolution with isospin. In this context, the structure of the transitional nucleus 29Mg is critical. The first quantitative measurements of the single particle structure of 29Mg are reported, using data from the d(28Mg,p gamma)29Mg reaction. Two key states carrying significant ell=3 (f-wave) strength were identified at 2.40 +/- 0.10 (Jpi = 5/2-) and 4.28 +/- 0.04 MeV (7/2-). New state-of-the-art shell model calculations have been performed and the predictions are compared in detail with the experimental results. Whilst the two lowest 7/2- levels are well described, the sharing of single-particle strength disagrees with experiment for both the 3/2- and 5/2- levels and there appear to be general problems with configurations involving the p3/2 neutron orbital and core-excited components. These conclusions are supported by an analysis of the neutron occupancies in the shell model calculations., Comment: 15 pages, 10 figures, 4 tables
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- 2019
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20. $\beta$ and $\beta$-delayed neutron decay of the $N=82$ nucleus $^{131}_{~49}$In$_{82}$
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Dunlop, R., Svensson, C. E., Andreoiu, C., Ball, G. C., Bernier, N., Bidaman, H., Bildstein, V., Bowry, M., Cross, D. S., Dillmann, I., Dunlop, M. R., Garcia, F. H., Garnsworthy, A. B., Garrett, P. E., Hackman, G., Henderson, J., Measures, J., Mücher, D., Olaizola, B., Ortner, K., Park, J., Petrache, C. M., Pore, J. L., Smith, J. K., Southall, D., Ticu, M., Turko, J., Whitmore, K., and Zidar, T.
- Subjects
Nuclear Experiment - Abstract
The half-lives of three $\beta$ decaying states of $^{131}_{~49}$In$_{82}$ have been measured with the GRIFFIN $\gamma$-ray spectrometer at the TRIUMF-ISAC facility to be $T_{1/2}(1/2^-)=328(15)$~ms, $T_{1/2}(9/2^+)=265(8)$~ms, and $T_{1/2}(21/2^+)=323(55)$~ms, respectively. The first observation of $\gamma$-rays following the $\beta n$ decay of $^{131}$In into $^{130}$Sn is reported. The $\beta$-delayed neutron emission probability is determined to be $P_{1n} = 12(7)\%$ for the $21/2^+$ state and $2.3(3)\%$ from the combined $1/2^-$ and $9/2^+$ states of $^{131}_{~49}$In$_{82}$ observed in this experiment. A significant expansion of the decay scheme of $^{131}$In, including 17 new excited states and 34 new $\gamma$-ray transitions in $^{131}_{~50}$Sn$_{81}$ is also reported. This leads to large changes in the deduced $\beta$ branching ratios to some of the low-lying states of $^{131}$Sn compared to previous work with implications for the strength of the first-forbidden $\beta$ transitions in the vicinity of doubly-magic $^{132}_{~50}$Sn$_{82}$., Comment: 14 pages, 15 figures, 5 tables
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- 2019
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21. Towards the understanding of the Ti/Al ratio role in solid-state reaction for ohmic contacts on n-GaN
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Guillemin, S., Messaoudene, S., Gergaud, P., Biscarrat, J., Roulet, P., Bernier, N., Templier, R., Souil, R., Zucchi, X., and Rodriguez, Ph.
- Published
- 2023
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22. Isospin symmetry in $B(E2)$ values: Coulomb excitation study of ${}^{21}$Mg
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Ruotsalainen, P., Henderson, J., Hackman, G., Sargsyan, G. H., Launey, K. D., Saxena, A., Srivastava, P. C., Stroberg, S. R., Grahn, T., Pakarinen, J., Ball, G. C., Julin, R., Greenlees, P. T., Smallcombe, J., Andreoiu, C., Bernier, N., Bowry, M., Buckner, M., Caballero-Folch, R., Chester, A., Cruz, S., Evitts, L. J., Frederick, R., Garnsworthy, A. B., Holl, M., Kurkjian, A., Kisliuk, D., Leach, K. G., McGee, E., Measures, J., Mücher, D., Park, J., Sarazin, F., Smith, J. K., Southall, D., Starosta, K., Svensson, C. E., Whitmore, K., Williams, M., and Wu, C. Y.
- Subjects
Nuclear Experiment - Abstract
The $T_z$~=~$-\frac{3}{2}$ nucleus ${}^{21}$Mg has been studied by Coulomb excitation on ${}^{196}$Pt and ${}^{110}$Pd targets. A 205.6(1)-keV $\gamma$-ray transition resulting from the Coulomb excitation of the $\frac{5}{2}^+$ ground state to the first excited $\frac{1}{2}^+$ state in ${}^{21}$Mg was observed for the first time. Coulomb excitation cross-section measurements with both targets and a measurement of the half-life of the $\frac{1}{2}^+$ state yield an adopted value of $B(E2;\frac{5}{2}^+\rightarrow\frac{1}{2}^+)$~=~13.3(4)~W.u. A new excited state at 1672(1)~keV with tentative $\frac{9}{2}^+$ assignment was also identified in ${}^{21}$Mg. This work demonstrates large difference of the $B(E2;\frac{5}{2}^+\rightarrow\frac{1}{2}^+)$ values between $T$~=~$\frac{3}{2}$, $A$~=~21 mirror nuclei. The difference is investigated in the shell-model framework employing both isospin conserving and breaking USD interactions and using modern \textsl{ab initio} nuclear structure calculations, which have recently become applicable in the $sd$ shell., Comment: 8 pages, 6 figures, submitted to Phys. Rev. C, Rapid Communication
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- 2018
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23. Characterization of electroless nickel-phosphorus plating for ultracold-neutron storage
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Akatsuka, H., Andalib, T., Bell, B., Berean-Dutcher, J., Bernier, N., Bidinosti, C.P., Cude-Woods, C., Currie, S.A., Davis, C.A., Franke, B., Gaur, R., Giampa, P., Hansen-Romu, S., Hassan, M.T., Hatanaka, K., Higuchi, T., Gibson, C., Ichikawa, G., Ide, I., Imajo, S., Ito, T.M., Jamieson, B., Kawasaki, S., Kitaguchi, M., Klassen, W., Korkmaz, E., Kuchler, F., Lang, M., Lavvaf, M., Lindner, T., Makela, M., Mammei, J., Mammei, R., Martin, J.W., Matsumiya, R., Miller, E., Mishima, K., Momose, T., Morawetz, S., Morris, C.L., Ong, H.J., O’Shaughnessy, C.M., Pereira-Wilson, M., Picker, R., Piermaier, F., Pierre, E., Schreyer, W., Sidhu, S., Stang, D., Tiepo, V., Vanbergen, S., Wang, R., Wong, D., and Yamamoto, N.
- Published
- 2023
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24. Half-Lives of Neutron Rich $^{130}$Cd and $^{131}$In
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Dunlop, R., Svensson, C. E., Andreoiu, C., Ball, G. C., Bernier, N., Bildstein, V., Bidaman, H., Boubel, P., Burbadge, C., Caballero-Folch, R., Dillmann, I., Dunlop, M. R., Evitts, L. J., Garcia, F. H., Garnsworthy, A. B., Garrett, P. E., Hackman, G., Hallam, S., Henderson, J., Ilyushkin, S., Jungclaus, A., Krücken, R., Lassen, J., Li, R., MacConnachie, E., MacLean, A. D., McGee, E., Moukaddam, M., Mücher, D., Olaizola, B., Ortner, K., Padilla-Rodal, E., Park, J., Paetkau, O., Pore, J. L., Radich, A. J., Ruotsalainen, P., Smallcombe, J., Smith, J. K., Teigelhöfer, A., Turko, J., Whitmore, K., and Zidar, T.
- Subjects
Nuclear Experiment - Abstract
The half-lives of isotopes around the $N=82$ shell closure are an important ingredient in astrophysical simulations and strongly influence the magnitude of the second $r$-process abundance peak in the $A\sim130$ region. The most neutron-rich $N=82$ nuclei are not accessible to the current generation of radioactive beam facilities and $r$-process simulations must therefore rely on calculations of the half-lives of the isotopes involved. Half-life measurements of the experimentally accessible nuclei in this region are important in order to benchmark these calculations. The half-life of $^{130}$Cd is particularly important as it is used to tune the Gamow-Teller quenching in shell-model calculations for the $\beta$ decay of other nuclei in this region. In this work, the GRIFFIN $\gamma$-ray spectrometer at the TRIUMF-ISAC facility was used to measure the half-life of $^{130}_{~48}$Cd$_{82}$ to be $T_{1/2}= 126(4)$ ms. In addition, the half-lives of the three $\beta$ decaying states of $^{131}_{~49}$In$_{82}$ were measured to be $T_{1/2}(1/2^-)=328(15)$ ms, $T_{1/2}(9/2^+)=265(8)$ ms, and $T_{1/2}(21/2^+)=323(50)$ ms, respectively, providing an important benchmark for half-life calculations in this region., Comment: Talk presented CIPANP2018. 9 pages, LaTeX, 5 pdf figures, 1 png figure
- Published
- 2018
25. The GRIFFIN Facility for Decay-Spectroscopy Studies at TRIUMF-ISAC
- Author
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Garnsworthy, A. B., Svensson, C. E., Bowry, M., Dunlop, R., MacLean, A. D., Olaizola, B., Smith, J. K., Ali, F. A., Andreoiu, C., Ash, J. E., Ashfield, W. H., Ball, G. C., Ballast, T., Bartlett, C., Beadle, Z., Bender, P. C., Bernier, N., Bhattacharjee, S. S., Bidaman, H., Bildstein, V., Bishop, D., Boubel, P., Braid, R., Brennan, D., Bruhn, T., Burbadge, C., Cheeseman, A., Chester, A., Churchman, R., Ciccone, S., Caballero-Folch, R., Cross, D. S., Cruz, S., Davids, B., Varela, A. Diaz, Dillmann, I., Dunlop, M. R., Evitts, L. J., Garcia, F. H., Garrett, P. E., Georges, S., Gillespie, S., Gudapati, R., Hackman, G., Hadinia, B., Hallam, S., Henderson, J., Ilyushkin, S. V., Jigmeddorj, B., Kilic, A. I., Kisliuk, D., Kokke, R., Kuhn, K., Kruecken, R., Kuwabara, M., Laffoley, A. T., Lafleur, R., Leach, K. G., Leslie, J. R., Linn, Y., Lim, C., MacConnachie, E., Mathews, A. R., McGee, E., Measures, J., Miller, D., Mills, W. J., Moore, W., Morris, D., Morrison, L. N., Moukaddam, M., Natzke, C. R., Ortner, K., Padilla-Rodal, E., Paetkau, O., Park, J., Patel, H. P., Pearson, C. J., Peters, E., Peters, E. E., Pore, J. L., Radich, A. J., Rajabali, M. M., Rand, E. T., Raymond, K., Rizwan, U., Ruotsalainen, P., Saito, Y., Sarazin, F., Shaw, B., Smallcombe, J., Southall, D., Starosta, K., Ticu, M., Timakova, E., Turko, J., Umashankar, R., Unsworth, C., Wang, Z. M., Whitmore, K., Wong, S., Yates, S. W., Zganjar, E. F., and Zidar, T.
- Subjects
Physics - Instrumentation and Detectors ,Nuclear Experiment - Abstract
Gamma-Ray Infrastructure For Fundamental Investigations of Nuclei, GRIFFIN, is a new high-efficiency $\gamma$-ray spectrometer designed for use in decay spectroscopy experiments with low-energy radioactive ion beams provided by TRIUMF's Isotope Separator and Accelerator (ISAC-I) facility. GRIFFIN is composed of sixteen Compton-suppressed large-volume clover-type high-purity germanium (HPGe) $\gamma$-ray detectors combined with a suite of ancillary detection systems and coupled to a custom digital data acquisition system. The infrastructure and detectors of the spectrometer as well as the performance characteristics and the analysis techniques applied to the experimental data are described.
- Published
- 2018
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26. Nonreciprocity in microwave optomechanical circuits
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Bernier, N. R., Tóth, L. D., Feofanov, A. K., and Kippenberg, T. J.
- Subjects
Quantum Physics ,Condensed Matter - Mesoscale and Nanoscale Physics ,Condensed Matter - Superconductivity - Abstract
Nonreciprocal devices such as isolators and circulators are necessary to protect sensitive apparatus from unwanted noise. Recently, a variety of alternatives were proposed to replace ferrite-based commercial technologies, with the motivation to be integrated with microwave superconducting quantum circuits. Here, we review isolators realized with microwave optomechanical circuits and present a gyrator-based picture to develop an intuition on the origin of nonreciprocity in these systems. Such nonreciprocal optomechanical schemes show promise as they can be extended to circulators and directional amplifiers, with perspectives to reach the quantum limit in terms of added noise., Comment: 7 pages, 3 figures; submitted as a contribution to a special issue titled "Magnet-less Nonreciprocity in Electromagnetics" to appear in IEEE Antennas and Wireless Propagation Letters
- Published
- 2018
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27. High-Precision Half-life Measurement for the Superallowed Fermi $\beta^+$ Emitter $^{22}$Mg
- Author
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Dunlop, M. R., Svensson, C. E., Ball, G. C., Leslie, J. R., Andreoiu, C., Bernier, N., Bidaman, H., Bildstein, V., Bowry, M., Burbadge, C., Caballero-Folch, R., Varela, A. Diaz, Dunlop, R., Garnsworthy, A. B., Garrett, P. E., Hackman, G., Jigmeddorj, B., Leach, K. G., MacLean, A. D., Olaizola, B., Measures, J., Natzke, C., Saito, Y., Smith, J. K., Turko, J., and Zidar, T.
- Subjects
Nuclear Experiment - Abstract
A high-precision half-life measurement for the superallowed Fermi $\beta^+$ emitter $^{22}$Mg was performed at the TRIUMF-ISAC facility using a 4$\pi$ proportional gas counter. The result of $T_{1/2} = 3.87400 \pm 0.00079$ s is a factor of 3 more precise than the previously adopted world average and resolves a discrepancy between the two previously published $^{22}$Mg half-life measurements., Comment: 7 pages, 9 figures
- Published
- 2017
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28. The effect of Ge content on structural evolution of Ge-rich GeSbTe alloys at increasing temperature
- Author
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Prazakova, L., Nolot, E., Martinez, E., Rouchon, D., Fillot, F., Bernier, N., Elizalde, R., Bernard, M., and Navarro, G.
- Published
- 2022
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29. Testing microscopically derived descriptions of nuclear collectivity: Coulomb excitation of 22Mg
- Author
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Henderson, J., Hackman, G., Ruotsalainen, P., Stroberg, S. R., Launey, K. D., Ali, F. A., Bernier, N., Bentley, M. A., Bowry, M., Cabellero-Folch, R., Evitts, L. J., Frederick, R., Garnsworthy, A. B., Garrett, P. E., Holt, J. D., Jigmeddorj, B., Kilic, A. I., Measures, J., Muecher, D., Olaizola, B., O'Sullivan, E., Paetkau, O., Park, J., Smallcombe, J., Svensson, C. E., Wu, C. Y., and Wadsworth, R.
- Subjects
Nuclear Experiment - Abstract
Many-body nuclear theory utilizing microscopic or chiral potentials has developed to the point that collectivity might be dealt with in an {\it ab initio} framework without the use of effective charges; for example with the proper evolution of operators, or alternatively, through the use of an appropriate and manageable subset of particle-hole excitations. We present a precise determination of $E2$ strength in $^{22}$Mg and its mirror $^{22}$Ne by Coulomb excitation, allowing for rigorous comparisons with theory. No-core symplectic shell-model calculations were performed and agree with the new $B(E2)$ values while in-medium similarity-renormalization-group calculations consistently underpredict the absolute strength, with the missing strength found to have both isoscalar and isovector components., Comment: 7 pages, 5 figures. To be submitted to Physics Letters B
- Published
- 2017
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30. Level attraction in a microwave optomechanical circuit
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Bernier, N. R., Tóth, L. D., Feofanov, A. K., and Kippenberg, T. J.
- Subjects
Condensed Matter - Mesoscale and Nanoscale Physics ,Quantum Physics - Abstract
Level repulsion - the opening of a gap between two degenerate modes due to coupling - is ubiquitous anywhere from solid state theory to quantum chemistry. In contrast, if one mode has negative energy, the mode frequencies attract instead. They converge and develop imaginary components, leading to an instability; an exceptional point marks the transition. This, however, only occurs if the dissipation rates of the two modes are comparable. Here we expose a theoretical framework for the general phenomenon and realize it experimentally through engineered dissipation in a multimode superconducting microwave optomechanical circuit. Level attraction is observed for a mechanical oscillator and a superconducting microwave cavity, while an auxiliary cavity is used for sideband cooling. Two exceptional points are demonstrated that could be exploited for their topological properties., Comment: 5 pages, 4 figures; includes Supplementary information
- Published
- 2017
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31. A maser based on dynamical backaction on microwave light
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Tóth, L. D., Bernier, N. R., Feofanov, A. K., and Kippenberg, T. J.
- Subjects
Quantum Physics - Abstract
The work of Braginsky introduced radiation pressure dynamical backaction, in which a mechanical oscillator that is parametrically coupled to an electromagnetic mode can experience a change in its rigidity and its damping rate. The finite cavity electromagnetic decay rate can lead to either amplification or cooling of the mechanical oscillator, and lead in particular to a parametric oscillatory instability, associated with regenerative oscillations of the mechanical oscillator, an effect limiting the circulating power in laser gravitational wave interferometers. These effects implicitly rely on an electromagnetic cavity whose dissipation rate vastly exceeds that of the mechanical oscillator, a condition naturally satisfied in most optomechanical systems. Here we consider the opposite limit, where the mechanical dissipation is engineered to dominate over the electromagnetic one, essentially reversing role of electromagnetic and mechanical degree of freedom. As a result, the electromagnetic field is now subject to dynamical backaction: the mechanical oscillator provides a feedback mechanism which modifies the damping rate of the electromagnetic cavity. We describe this phenomenon in the spirit of Braginsky's original description, invoking finite cavity delay and highlighting the role of dissipation. Building on previous experimental work, we demonstrate this dynamical backaction on light in a superconducting microwave optomechanical circuit. In particular, we drive the system above the parametric instability threshold of the microwave mode, leading to maser action and demonstrate injection locking of the maser, which stabilizes its frequency and reduces its noise., Comment: Manuscript prepared for a special issue of Physics Letters A in memory of V. Braginsky
- Published
- 2017
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32. MoS2-assisted growth of highly-oriented AlN thin films by low-temperature van der Waals epitaxy.
- Author
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Patouillard, J., Bernard, M., Cadot, S., Gassilloud, R., Bernier, N., Grenier, A., Mantoux, A., Blanquet, E., Martin, F., Raynaud, C., and Gianesello, F.
- Subjects
ALUMINUM nitride ,SUBSTRATES (Materials science) ,TRANSITION metals ,THIN films ,ACOUSTIC devices - Abstract
Aluminum nitride (AlN) is a wide bandgap material used in acoustic devices, piezo- micro-electromechanical system and is promising for other electronic applications. However, for most applications, the AlN crystalline quality obtained by PVD or MOCVD is insufficient, and suitable growth substrates providing an adapted lattice match and coefficient of thermal expansion are limited. Alternatively, monocrystalline AlN wafers are not yet available in 200/300 mm sizes and suffer from high costs and quality issues. Here, we propose a novel approach involving a two-dimensional transition metal dichalcogenide (TMD) material as a seed layer, which displays an excellent lattice matching with AlN (>98%) allowing a strong enhancement in the c axis texture of sputtered AlN layers on Si(100)/SiO
2 thermal oxide (500 nm) substrates. We have successfully demonstrated an eightfold improvement of the AlN (002) rocking curve compared to reference samples grown on thermal SiO2 , thus providing a relevant and cost-effective process for the large-scale deployment of high-quality III-N materials on silicon-based substrates. [ABSTRACT FROM AUTHOR]- Published
- 2024
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33. Nonreciprocal reconfigurable microwave optomechanical circuit
- Author
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Bernier, N. R., Tóth, L. D., Koottandavida, A., Ioannou, M., Malz, D., Nunnenkamp, A., Feofanov, A. K., and Kippenberg, T. J.
- Subjects
Quantum Physics ,Condensed Matter - Mesoscale and Nanoscale Physics ,Condensed Matter - Superconductivity - Abstract
Devices that achieve nonreciprocal microwave transmission are ubiquitous in radar and radio-frequency communication systems, and commonly rely on magnetically biased ferrite materials. Such devices are also indispensable in the readout chains of superconducting quantum circuits as they protect sensitive quantum systems from the noise emitted by readout electronics. Since ferrite-based nonreciprocal devices are bulky, lossy, and require large magnetic fields, there has been significant interest in magnetic-field-free on-chip alternatives, such as those recently implemented using Josephson junctions. Here we realise reconfigurable nonreciprocal transmission between two microwave modes using purely optomechanical interactions in a superconducting electromechanical circuit. We analyse the transmission as well as the noise properties of this nonreciprocal circuit. The scheme relies on the interference in two mechanical modes that mediate coupling between microwave cavities. Finally, we show how quantum-limited circulators can be realized with the same principle. The technology can be built on-chip without any external magnetic field, and is hence fully compatible with superconducting quantum circuits. All-optomechanically-mediated nonreciprocity demonstrated here can also be extended to implement directional amplifiers, and it forms the basis towards realising topological states of light and sound., Comment: 8 pages of main text + 7 pages of supplementary information
- Published
- 2016
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34. Carbon ion implantation as healing strategy for improved reliability in phase-change memory arrays
- Author
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Bourgeois, G., Meli, V., Al Mamun, F., Mazen, F., Nolot, E., Martinez, E., Barnes, J.-P., Bernier, N., Jannaud, A., Laulagnet, F., Hemard, B., Castellani, N., Bernard, M., Sabbione, C., Milesi, F., Magis, T., Socquet-Clerc, C., Coig, M., Garrione, J., Cyrille, M.-C., Charpin, C., Navarro, G., and Andrieu, F.
- Published
- 2021
- Full Text
- View/download PDF
35. Evolution of the Ni0.9Pt0.1/Si system under annealing via nano-crystalline textured phases.
- Author
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Guillemin, S., Gergaud, P., Bernier, N., Merlin, M., Delwail, C., Minoret, S., Famulok, R., Gregoire, M., Nemouchi, F., and Rodriguez, Ph.
- Subjects
X-ray diffraction ,TRANSMISSION electron microscopy ,DIFFUSION control ,THIN films ,NUCLEATION - Abstract
The reaction of a Ni 0.9 Pt 0.1 7 nm-thick thin film with the underlying Si(001) substrate as a function of the annealing temperature was studied using in situ XRD techniques as well as ex situ advanced XRD and TEM imaging on quenched samples. It was found that the Ni 0.9 Pt 0.1 /Si system initially evolves accordingly to diffusion controlled reactions via the development of nano-crystalline Ni-rich Ni 1 − x (Pt) Si x phases that combine the ability of fast kinetic growth and texture inheritance. The system remains then stable over some tens of degrees before Ni(Pt)Si nucleation occurs, once the related energetic barrier is overcome. It was additionally found that this newly observed phase sequence remains valid up to Ni 0.9 Pt 0.1 deposited layer thicknesses of about 16 nm, which is remarkable for such systems. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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- View/download PDF
36. A dissipative quantum reservoir for microwave light using a mechanical oscillator
- Author
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Tóth, L. D., Bernier, N. R., Nunnenkamp, A., Feofanov, A. K., and Kippenberg, T. J.
- Subjects
Quantum Physics ,Condensed Matter - Mesoscale and Nanoscale Physics ,Condensed Matter - Superconductivity - Abstract
Isolation of a system from its environment is often desirable, from precision measurements to control of individual quantum systems; however, dissipation can also be a useful resource. Remarkably, engineered dissipation enables the preparation of quantum states of atoms, ions or superconducting qubits as well as their stabilization. This is achieved by a suitably engineered coupling to a dissipative cold reservoir formed by electromagnetic modes. Similarly, in the field of cavity electro- and optomechanics, the control over mechanical oscillators utilizes the inherently cold, dissipative nature of the electromagnetic degree of freedom. Breaking from this paradigm, recent theoretical work has considered the opposite regime in which the dissipation of the mechanical oscillator dominates and provides a cold, dissipative reservoir to an electromagnetic mode. Here we realize this reversed dissipation regime in a microwave cavity optomechanical system and realize a quasi-instantaneous, cold reservoir for microwave light. Coupling to this reservoir enables to manipulate the susceptibility of the microwave cavity, corresponding to dynamical backaction control of the microwave field. Additionally, we observe the onset of parametric instability, i.e. the stimulated emission of microwaves (masing). Equally important, the reservoir can function as a useful quantum resource. We evidence this by employing the engineered cold reservoir to implement a large gain (above 40 dB) phase preserving microwave amplifier that operates 0.87 quanta above the limit of added noise imposed by quantum mechanics. Such a dissipative cold reservoir forms the basis of microwave entanglement schemes, the study of dissipative quantum phase transitions, amplifiers with unlimited gain-bandwidth product and non-reciprocal devices, thereby extending the available toolbox of quantum-limited microwave manipulation techniques., Comment: 9 pages, 5 figures (main text); Supplementary Information included
- Published
- 2016
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37. Influence of dual Ge/C pre-amorphization implantation on the Ni1−xPtxSi phase nucleation and growth mechanisms
- Author
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Guillemin, S., Gergaud, P., Bernier, N., Lachal, L., Mazen, F., Jannaud, A., Nemouchi, F., and Rodriguez, Ph.
- Published
- 2021
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38. Storm surges and extreme sea levels: Review, establishment of model intercomparison and coordination of surge climate projection efforts (SurgeMIP)
- Author
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Bernier, N. B. Hemer, M. Mori, N. Appendini, C. M. Breivik, O. de Camargo, R. Casas-Prat, M. Duong, T. M. Haigh, I. D. Howard, T. Hernaman, V. Huizy, O. Irish, J. L. Kirezci, E. Kohno, N. Lee, J. W. McInnes, K. L. Meyer, E. I. Marcos, M. Marsooli, R. Martin Oliva, A. Menendez, M. Moghimi, S. Muis, S. Polton, J. A. Pringle, W. J. Ranasinghe, R. Saillour, T. Smith, G. Tadesse, M. G. Swail, V. Tomoya, S. Voukouvalas, E. Wahl, T. Wang, P. Weisse, R. Westerink, J. J. Young, I. Zhang, Y. J. and Bernier, N. B. Hemer, M. Mori, N. Appendini, C. M. Breivik, O. de Camargo, R. Casas-Prat, M. Duong, T. M. Haigh, I. D. Howard, T. Hernaman, V. Huizy, O. Irish, J. L. Kirezci, E. Kohno, N. Lee, J. W. McInnes, K. L. Meyer, E. I. Marcos, M. Marsooli, R. Martin Oliva, A. Menendez, M. Moghimi, S. Muis, S. Polton, J. A. Pringle, W. J. Ranasinghe, R. Saillour, T. Smith, G. Tadesse, M. G. Swail, V. Tomoya, S. Voukouvalas, E. Wahl, T. Wang, P. Weisse, R. Westerink, J. J. Young, I. Zhang, Y. J.
- Abstract
Coastal flood damage is primarily the result of extreme sea levels. Climate change is expected to drive an increase in these extremes. While proper estimation of changes in storm surges is essential to estimate changes in extreme sea levels, there remains low confidence in future trends of surge contribution to extreme sea levels. Alerting local populations of imminent extreme sea levels is also critical to protecting coastal populations. Both predicting and projecting extreme sea levels require reliable numerical prediction systems. The SurgeMIP (surge model intercomparison) community has been established to tackle such challenges. Efforts to intercompare storm surge prediction systems and coordinate the community's prediction and projection efforts are introduced. An overview of past and recent advances in storm surge science such as physical processes to consider and the recent development of global forecasting systems are briefly introduced. Selected historical events and drivers behind fast increasing service and knowledge requirements for emergency response to adaptation considerations are also discussed. The community's initial plans and recent progress are introduced. These include the establishment of an intercomparison project, the identification of research and development gaps, and the introduction of efforts to coordinate projections that span multiple climate scenarios.
- Published
- 2024
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39. WET and Siconi® cleaning sequences for SiGe epitaxial regrowth
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Raynal, Pierre-Edouard, Loup, V., Vallier, L., Bernier, N., Hartmann, J.M., and Besson, P.
- Published
- 2020
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40. Fast-timing Investigation of \(A=128\) Isobars Populated in the \(\beta \)-decay of \(^{128}\)Cd
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Llanos-Expósito, M., primary, Fraile, L.M., additional, Benito, J., additional, Acosta, J., additional, Algora, A., additional, Andel, B., additional, Andreyev, A.N., additional, Antalic, S., additional, Bark, R.A., additional, Bernerd, C., additional, Bernier, N., additional, Bhengu, B., additional, Bittner, D., additional, Borge, M.J.G., additional, Briz, J.A., additional, Chrysalidis, K., additional, Cocolios, T.E., additional, Costache, C., additional, Cubiss, J.G., additional, De Witte, H., additional, Encina, N., additional, Esmaylzadeh, A., additional, Favier, Z., additional, Fernández, D., additional, Ferrera, C., additional, Fynbo, H.O.U., additional, García-Távora, V., additional, Georgiev, G., additional, Górska, M., additional, Heinke, R., additional, Herraiz, J.L., additional, Illana, A., additional, Jones, P., additional, Judson, D.S., additional, Jungclaus, A., additional, Karny, M., additional, Korgul, A., additional, Köster, U., additional, Kröll, Th., additional, Labiche, M., additional, Lalkovski, S., additional, Lesch, B., additional, Ley, M., additional, Lică, R., additional, Madurga, M., additional, Mărginean, N., additional, Marsh, B.A., additional, Miernik, K., additional, Mihai, C., additional, Mikolajczuk, M., additional, Mišt, J., additional, Murias, J.R., additional, Nácher, E., additional, Neacsu, C., additional, Nouvilas, V.M., additional, Ntshangase, S., additional, Olaizola, B., additional, Orce, J.N., additional, Page, C., additional, Pakarinen, J., additional, Papadakis, P., additional, Perea, A., additional, Piersa-Siłkowska, M., additional, Podolyak, Zs., additional, Rog, J., additional, Rothe, S., additional, Rozwoda, B., additional, Sánchez-Tembleque, V., additional, Solak, K., additional, Stegemann, S., additional, Stepaniuk, M., additional, Stoica, A., additional, Stryjczyk, M., additional, Tengblad, O., additional, Turturica, A., additional, Turturica, G., additional, Udías, J.M., additional, Ujeniuc, S., additional, Van Duppen, P., additional, von Tresckow, M., additional, Vasilev, I., additional, Warr, N., additional, Yue, Z., additional, and Zajda, S., additional
- Published
- 2024
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41. Crystallographic reconstruction study of the effects of finish rolling temperature on the variant selection during bainite transformation in C-Mn high-strength steels
- Author
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Bernier, N., Bracke, L., Malet, L., and Godet, S.
- Subjects
Condensed Matter - Materials Science - Abstract
The effect of finish rolling temperature (FRT) on the austenite- () to-bainite () phase transformation is quantitatively investigated in high-strength C-Mn steels. In particular, the present study aims to clarify the respective contributions of the conditioning during the hot rolling and the variant selection (VS) during the phase transformation to the inherited texture. To this end, an alternative crystallographic reconstruction procedure, which can be directly applied to experimental electron backscatter diffraction (EBSD) mappings, is developed by combining the best features of the existing models: the orientation relationship (OR) refinement, the local pixel-by-pixel analysis and the nuclei identification and spreading strategy. The applicability of this method is demonstrated on both quenching and partitioning (Q&P) and as-quenched lath-martensite steels. The results obtained on the C-Mn steels confirm that the sample finish rolled at the lowest temperature (829{\deg}C) exhibits the sharpest transformation texture. It is shown that this sharp texture is exclusively due to a strong VS from parent brass {110}<1-12>, S {213}<-3-64> and Goss {110}<001> grains, whereas the VS from the copper {112}<-1-11> grains is insensitive to the FRT. In addition, a statistical VS analysis proves that the habit planes of the selected variants do not systematically correspond to the predicted active slip planes using the Taylor model. In contrast, a correlation between the Bain group to which the selected variants belong and the FRT is clearly revealed, regardless of the parent orientation. These results are discussed in terms of polygranular accommodation mechanisms, especially in view of the observed development in the hot-rolled samples of high-angle grain boundaries with misorientation axes between <111> and <110> .
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- 2013
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42. The GRIFFIN facility for Decay-Spectroscopy studies at TRIUMF-ISAC
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Garnsworthy, A.B., Svensson, C.E., Bowry, M., Dunlop, R., MacLean, A.D., Olaizola, B., Smith, J.K., Ali, F.A., Andreoiu, C., Ash, J.E., Ashfield, W.H., Ball, G.C., Ballast, T., Bartlett, C., Beadle, Z., Bender, P.C., Bernier, N., Bhattacharjee, S.S., Bidaman, H., Bildstein, V., Bishop, D., Boubel, P., Braid, R., Brennan, D., Bruhn, T., Burbadge, C., Cheeseman, A., Chester, A., Churchman, R., Ciccone, S., Caballero-Folch, R., Cross, D.S., Cruz, S., Davids, B., Varela, A. Diaz, Dillmann, I., Dunlop, M.R., Evitts, L.J., Garcia, F.H., Garrett, P.E., Georges, S., Gillespie, S., Gudapati, R., Hackman, G., Hadinia, B., Hallam, S., Henderson, J., Ilyushkin, S.V., Jigmeddorj, B., Kilic, A.I., Kisliuk, D., Kokke, R., Kuhn, K., Krücken, R., Kuwabara, M., Laffoley, A.T., Lafleur, R., Leach, K.G., Leslie, J.R., Linn, Y., Lim, C., MacConnachie, E., Mathews, A.R., McGee, E., Measures, J., Miller, D., Mills, W.J., Moore, W., Morris, D., Morrison, L.N., Moukaddam, M., Natzke, C.R., Ortner, K., Padilla-Rodal, E., Paetkau, O., Park, J., Patel, H.P., Pearson, C.J., Peters, E., Peters, E.E., Pore, J.L., Radich, A.J., Rajabali, M.M., Rand, E.T., Raymond, K., Rizwan, U., Ruotsalainen, P., Saito, Y., Sarazin, F., Shaw, B., Smallcombe, J., Southall, D., Starosta, K., Ticu, M., Timakova, E., Turko, J., Umashankar, R., Unsworth, C., Wang, Z.M., Whitmore, K., Wong, S., Yates, S.W., Zganjar, E.F., and Zidar, T.
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- 2019
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43. Few Graphene layer/Carbon-Nanotube composite Grown at CMOS-compatible Temperature
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Jousseaume, V., Cuzzocrea, J., Bernier, N., and Renard, Vincent Thomas Francois
- Subjects
Condensed Matter - Materials Science - Abstract
We investigate the growth of the recently demonstrated composite material composed of vertically aligned carbon nanotubes capped by few graphene layers. We show that the carbon nanotubes grow epitaxially under the few graphene layers. By using a catalyst and gaseous carbon precursor different from those used originally we establish that such unconventional growth mode is not specific to a precise choice of catalyst-precursor couple. Furthermore, the composite can be grown using catalyst and temperatures compatible with CMOS processing (T < 450\degree C)., Comment: 4 pages, 4 figures
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- 2011
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44. Recoil distance method lifetime measurements at TRIUMF-ISAC using the TIGRESS Integrated Plunger
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Chester, A., Ball, G.C., Bernier, N., Cross, D.S., Domingo, T., Drake, T.E., Evitts, L.J., Garcia, F.H., Garnsworthy, A.B., Hackman, G., Hallam, S., Henderson, J., Henderson, R., Krücken, R., MacConnachie, E., Moukaddam, M., Padilla-Rodal, E., Paetkau, O., Pore, J.L., Rizwan, U., Ruotsalainen, P., Shoults, J., Smallcombe, J., Smith, J.K., Starosta, K., Svensson, C.E., Van Wieren, K., Williams, J., and Williams, M.
- Published
- 2018
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45. Recrystallization of thick implanted GeSn layers with nanosecond laser annealing.
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Casiez, L., Bernier, N., Chrétien, J., Richy, J., Rouchon, D., Bertrand, M., Mazen, F., Frauenrath, M., Chelnokov, A., Hartmann, J. M., Calvo, V., Pauc, N., Reboud, V., and Acosta Alba, P.
- Subjects
- *
LASER annealing , *ULTRAVIOLET lasers , *EPITAXIAL layers , *TIN - Abstract
We investigate the recrystallization of thick phosphorus-implanted GeSn layers using 308 nm Ultraviolet Nanosecond Laser Annealing (UV-NLA). We identify the optimal annealing conditions leading to the reconstruction of Ge0.92Sn0.08 crystal amorphized by dopant implantation. The fully recrystallized GeSn layers present specific structures with localized tin and strain variations. Above the non-amorphized and unmelted Ge0.92Sn0.08 seed layer, a first highly tensile strained GeSn sublayer is formed, with a tin gradient from 2.5% up to 10.5%. Closer to the surface, a second sublayer consists of tin-enriched vertical structures in a Ge0.93Sn0.07 matrix. Laser annealing enables us to reverse the strain of the GeSn layer. The initial GeSn presents a compressive strain of −0.10%, while the recrystallized Ge0.93Sn0.07 matrix is tensile strained at 0.39%. UV-NLA presents the advantages of (i) local annealing that recrystallizes amorphized GeSn layers after implantation without excessive tin segregation and (ii) reversing the strain of epitaxial GeSn layers from compressive to tensile. Our results open up promising perspectives for the integration of GeSn mid-IR photonic devices. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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46. Evolution of the Ni0.9Pt0.1/Si system under annealing via nano-crystalline textured phases
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Guillemin, S., primary, Gergaud, P., additional, Bernier, N., additional, Merlin, M., additional, Delwail, C., additional, Minoret, S., additional, Famulok, R., additional, Gregoire, M., additional, Nemouchi, F., additional, and Rodriguez, Ph., additional
- Published
- 2023
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47. Fabrication and electrical characterizations of SGOI tunnel FETs with gate length down to 50 nm
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Le Royer, C., Villalon, A., Hutin, L., Martinie, S., Nguyen, P., Barraud, S., Glowacki, F., Allain, F., Bernier, N., Cristoloveanu, S., and Vinet, M.
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- 2016
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48. New Opportunities in Decay Spectroscopy with the GRIFFIN and DESCANT Arrays
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Bildstein, V., Andreoiu, C., Ball, G.C., Ballast, T., Bartlett, C., Bender, P.C., Bernier, N., Bianco, L., Bishop, D., Brennan, D., Bruhn, T., Cheeseman, A., Churchman, R., Ciccone, S., Davids, B., Demand, G., Dillmann, I., Garnsworthy, A.B., Garrett, P.E., Georges, S., Hackman, G., Hadinia, B., Kokke, R., Krücken, R., Linn, Y., Lim, C., Martin, J.-P., Miller, D., Mills, W.J., Morrison, L.N., Ohlmann, C.A., Park, J., Pearson, C.J., Pore, J.L., Rajabali, M.M., Rand, E.T., Rizwan, U., Sarazin, F., Shaw, B., Starosta, K., Svensson, C.E., Sumithrarachchi, C., Unsworth, C., Voss, P., Wang, Z.M., Williams, J., Wong, J., and Wong, S.
- Published
- 2015
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49. Soil, humipedon, forest life and management
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Zampedri, R., Bernier, N., Zanella, A., Giannini, R., Menta, C., Visentin, F., Mairota, P., Mei, G., Zandegiacomo, G., Carollo, S., Brandolese, A., and Ponge, J.
- Subjects
Soil functioning ,Settore AGR/05 - ASSESTAMENTO FORESTALE E SELVICOLTURA ,Humipedon ,Forest soil ,Soil biodiversity ,Spruce forest ,Humus ,Forest dynamics - Published
- 2023
50. Enhanced thermal stability of Ni/GeSn system using pre-amorphization by implantation.
- Author
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Quintero, A., Mazen, F., Gergaud, P., Bernier, N., Hartmann, J.-M., Reboud, V., Cassan, E., and Rodriguez, Ph.
- Subjects
THERMAL stability ,ION implantation ,SURFACE morphology ,X-ray diffraction ,GERMANIDES ,GERMANIUM films - Abstract
Improving the thermal stability of Ni/GeSn intermetallics is of great importance to avoid surface degradation and Sn segregation. For this purpose, we studied the effects of pre-amorphization by ion implantation (PAI) of GeSn layers prior to metallization. The impact of Si, Ge, C, or Ge + C PAI was evaluated in terms of phase sequence, morpohological, and electrical evolution during the solid-state reaction. The overall phase sequence, followed by in situ x-ray diffraction, was comparable with or without PAI and went as follows: the Ni 5 (GeSn) 3 hexagonal phase was obtained first, followed by the mono-stanogermanide phase: Ni(GeSn). Nevertheless, the threshold temperature for phase formation varied. These variations, depending on the nature of the implanted ions, can be related to kinetic and/or thermodynamic factors as supported by the analysis of bibliography for silicides and germanides. Additionally, it was reported that the use of Si or Ge implantation did not significantly impacted the surface morphology of the layers. On the other hand, the implantation of C positively impacts the surface morphology evolution by delaying Sn long-range diffusion and Ni(GeSn) agglomeration. This trend was then highly beneficial for preserving electrical stability in an enhanced process window. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
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