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The 24Mg(p,α)21 Na transfer reaction has been previously studied for a spectroscopic study of 21Na [Cha et al., Phys. Rev. C 96, 025810 (2017)]. In this follow-up analysis, the proton decays of the excited states of the radionuclide 21Na, which were measured simultaneously, are reported. By investigating the coincidence between the reaction α-particles and decay protons, we were able to identify three groups of events that are associated with the energy levels in 20Ne. The 20Ne excitation energy plot was obtained as a result. The four lowest known energy levels in 20Ne (the ground state and excited states at Ex = 1.633, 4.247 and 4.966 MeV) were clearly observed.

The neutron inelastic scattering of carbon-12, populating the Hoyle state, is a reaction of interest 17 for the triple-alpha process. The inverse process (neutron upscattering) can enhance the Hoyle state’s decay rate to the bound states of 12 18 C, effectively increasing the overall triple-alpha reaction rate. 19 The cross section of this reaction is impossible to measure experimentally but has been determined 20 here at astrophysically-relevant energies for the first time using detailed balance. This cross section 21 will inform astrophysical models on the importance of neutron upscattering in neutron-rich stellar 22 environments. 23 Using a highly-collimated monoenergetic beam of neutrons incident on the Texas Active Target 24 Time Projection Chamber (TexAT TPC) filled with CO2 gas, the 3α-particles (arising from the decay 25 of the Hoyle state following inelastic scattering) were measured and a cross section was extracted 26 between En = 8.15 MeV and En = 10.0 MeV. The cross section above the threshold was dominated by a few resonances in 13 27 C around Ex = 13.5 MeV. This has a significant effect on the contribution 28 of neutron upscattering in stellar environments. 29 The neutron-upscattering enhancement is observed to be much smaller than previously expected. 30 For a temperature of 1 GK, the total enhancement factor, from upscattering to the ground state and 31 first-excited state, was seen to be 5, rising to around 46 at 10 GK thereby exceeding the contribution 32 from proton enhancement. The importance of the neutron-upscattering enhancement may therefore 33 not be significant aside from in very particular astrophysical sites (e.g. neutron star mergers).

Decay protons from excited states in $^{21}\mathrm{Na}$ populated through a previously reported $^{24}\mathrm{Mg}(p,\ensuremath{\alpha})^{21}\mathrm{Na}$ transfer reaction [Cha et al., Phys. Rev. C 96, 025810 (2017)] were analyzed to extract the proton branching ratios of the energy levels. By utilizing 31-MeV proton beams from the Holifield Radioactive Ion Beam Facility of Oak Ridge National Laboratory and isotopically enriched $^{24}\mathrm{Mg}$ solid targets, the decay protons were detected in coincidence with $\ensuremath{\alpha}$ particles from the $(p,\ensuremath{\alpha})$ reaction using a silicon strip detector array. Proton decay branching ratios of several $^{21}\mathrm{Na}$ levels were deduced for the $p0$ and $p1$ decay channels to the ground and first excited states in $^{20}\mathrm{Ne}$, respectively.

The $$^{22}\hbox {Na}(p,\gamma )^{23}\hbox {Mg}$$ reaction is responsible for destruction of the long-lived radionuclide $$^{22}\hbox {Na}$$ produced during nova explosions. Since the reaction proceeds through resonances from levels in $$^{23}\hbox {Mg}$$ above the proton threshold at 7.581 MeV, the properties of these levels such as excitation energies, spins, and parities are crucial ingredients to determine the $$^{22}\hbox {Na}(p,\gamma )^{23}\hbox {Mg}$$ reaction rate. Despite recent studies of these levels, their spins are not well constrained in many cases. We have measured the $$^{24}\mathrm{Mg}(p,d)^{23}\hbox {Mg}$$ transfer reaction to determine spectroscopic properties of these levels at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory. The spin of the $$E_{x}$$ = 7.788 MeV level in $$^{23}\hbox {Mg}$$ is constrained to be $$J^{\pi }$$ = (3/2$$^+$$, 5/2$$^+$$) through the present work. The astrophysical $$^{22}\hbox {Na}(p,\gamma )^{23}\hbox {Mg}$$ reaction rate at nova temperatures is updated accordingly. Nova nucleosynthesis model calculations using the newly updated $$^{22}\hbox {Na}(p,\gamma )^{23}\hbox {Mg}$$ reaction rate shows that the final weighted abundance of the radionuclide $$^{22}\hbox {Na}$$ is increased by 42% compared to that obtained by using the previous $$^{22}\hbox {Na}(p,\gamma )^{23}\hbox {Mg}$$ reaction rate of Sallaska et al. for a 1.35 $$M_{\odot }$$ ONeMg white dwarf.

In atomic nuclei, the spin-orbit interaction originates from the coupling of the orbital motion of a nucleon with its intrinsic spin. Recent experimental and theoretical works have suggested a weakening of the spin-orbit interaction in neutron-rich nuclei far from stability. To study this phenomenon, we have investigated the spin-orbit energy splittings of single-hole and single-particle valence neutron orbits of 132Sn. The spectroscopic strength of single-hole states in 131Sn was determined from the measured differential cross sections of the tritons from the neutron-removing 132Sn(d, t)131Sn reaction, which was studied in inverse kinematics at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory. The spectroscopic factors of the lowest 3/2+, 1/2+ and 5/2+ states were found to be consistent with their maximal values of (2j+1), confirming the robust N=82 shell closure at 132Sn. We compared the spin-orbit splitting of neutron single-hole states in 131Sn to those of single-particle states in 133Sn determined in a recent measurement of the 132Sn(d, p)133Sn reaction. We found a significant reduction of the energy splitting of the weakly bound 3p orbits compared to the well-bound 2d orbits, and that all the observed energy splittings can be reproduced remarkably well by calculations using a one-body spin-orbit interaction and a Woods–Saxon potential of standard radius and diffuseness. The observed reduction of spin-orbit splitting can be explained by the extended radial wavefunctions of the weakly bound orbits, without invoking a weakening of the spin-orbit strength. Keywords: Nuclear structure, Spin-orbit interaction, Transfer reactions, Doubly-magic nuclei, Shell model

Direct measurements of ( α , p ) reactions of astrophysical interest with radioactive beams presents serious challenges because of the difficult nature of helium targets and the typical low intensities of the beams. To address this, a new technique has been developed for measurements of low-energy ( α , p ) reactions with heavy ion beams using an extended 4 He gas target and a newly developed gas recirculating system. The system was used to measure the 4 He(19F, 1 H)22Ne reaction as a demonstration. Excitation functions of the 19F( α , p )22Ne and 19F( α , p ′ )22Ne ∗ reactions were successfully measured to show the viability of this technique. Details of the approach and future plans are given.

Results are presented from the first neutron-transfer measurement on $^{80}\mathrm{Ge}$ using an exotic beam from the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory. Newly measured spins and spectroscopic factors of low-lying states of $^{81}\mathrm{Ge}$ are determined, and the neutron capture cross section on $^{80}\mathrm{Ge}$ was calculated in a direct-semidirect model to provide a more realistic ($n,\ensuremath{\gamma}$) reaction rate for $r$-process simulations. Furthermore, a region of shape coexistence around $N\ensuremath{\approx}50$ is confirmed and implications for the magic nature of $^{78}\mathrm{Ni}$ are discussed.

The $^{15}$O($\alpha$,$\gamma$)$^{19}$Ne reaction is responsible for breakout from the hot CNO cycle in Type I x-ray bursts. Understanding the properties of resonances between $E_x = 4$ and 5 MeV in $^{19}$Ne is crucial in the calculation of this reaction rate. The spins and parities of these states are well known, with the exception of the 4.14- and 4.20-MeV states, which have adopted spin-parities of 9/2$^-$ and 7/2$^-$, respectively. Gamma-ray transitions from these states were studied using triton-$\gamma$-$\gamma$ coincidences from the $^{19}$F($^{3}$He,$t\gamma$)$^{19}$Ne reaction measured with GODDESS (Gammasphere ORRUBA Dual Detectors for Experimental Structure Studies) at Argonne National Laboratory. The observed transitions from the 4.14- and 4.20-MeV states provide strong evidence that the $J^\pi$ values are actually 7/2$^-$ and 9/2$^-$, respectively. These assignments are consistent with the values in the $^{19}$F mirror nucleus and in contrast to previously accepted assignments.

We report the coating of metal-free graphitic carbon nitride (g-C3N4) onto titanium dioxide (TiO2) nanorods via a thermal evaporation method. Prior to g-C3N4 coating, TiO2 nanoclusters were grown on TiO2 nanorods to enhance the surface area by dipping in a TiCl3 solution for 12, 24 and 36 h. The prepared films were analyzed to assess the improvement in absorbance and reduction in recombination losses. Nanoclustered TiO2 grown for 24 h and then coated with a g-C3N4 film (i.e., TC_24h_CN) had the highest photocurrent of 235 and 290 μA, respectively, when measured by transient photocurrent and linear sweep voltammetry techniques. The enhanced performance resulted from a reduced recombination of electron-hole pairs. The TC_24h_CN film displayed an excellent photoresponse over 15 h of exposure to visible light and hence could potentially be used in water purification device technology.

The astrophysical F 18 ( p , α ) O 15 rate determines, in large part, the extent to which the observable radioisotope 18 F is produced in novae. This rate, however, has been extremely uncertain owing to the unknown properties of a strong subthreshold resonance and its possible interference with higher-lying resonances. The new Jet Experiments in Nuclear Structure and Astrophysics (JENSA) gas-jet target has been used for the first time to determine the spin of this important resonance and significantly reduce uncertainties in the F 18 ( p , α ) O 15 rate.

To take full advantage of advanced exotic beam facilities, target technology must also be advanced. Particularly important to the study of astrophysical reaction rates is the creation of localized and dense targets of hydrogen and helium. The Jet Experiments in Nuclear Structure and Astrophysics (JENSA) gas-jet target has been constructed for this purpose. JENSA was constructed at Oak Ridge National Laboratory (ORNL) where it was tested and characterized, and has now moved to the ReA3 reaccelerated beam hall at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University for use with radioactive beams.

The Jet Experiments in Nuclear Structure and Astrophysics (JENSA) gas-jet target was used to perform spectroscopic studies of $^{20}\mathrm{Ne}+p$ reactions. Levels in $^{19}\mathrm{Ne}$ were probed via the $^{20}\mathrm{Ne}(p,d)^{19}\mathrm{Ne}$ reaction to constrain the astrophysical rate of the $^{18}\mathrm{F}(p,\ensuremath{\alpha})^{15}\mathrm{O}$ reaction. Additionally, the first spectroscopic study of the $^{20}\mathrm{Ne}(p,^{3}\mathrm{He})^{18}\mathrm{F}$ reaction was performed. Angular distribution data were used to determine or confirm the spins of several previously observed levels, and the existence of a strong subthreshold $^{18}\mathrm{F}(p,\ensuremath{\alpha})^{15}\mathrm{O}$ resonance was verified.

The $^{24}\mathrm{Mg}(p,\ensuremath{\alpha})^{21}\mathrm{Na}$ reaction was measured at the Holifield Radioactive Ion Beam Facility of the Oak Ridge National Laboratory to study the spectroscopy of the radionuclide $^{21}\mathrm{Na}$. A 31-MeV proton beam from the 25 MV tandem accelerator bombarded isotopically enriched $^{24}\mathrm{Mg}$ targets. Recoiling $^{4}\mathrm{He}$ particles were identified by an annular silicon strip detector array. Two energy levels at ${E}_{x}=6.594$ and 7.132 MeV were observed for the first time. By comparing the experimentally obtained angular distributions and distorted wave Born approximation calculations, the spins and parities of $^{21}\mathrm{Na}$ energy levels were constrained. The astrophysically-important $^{17}\mathrm{F}(\ensuremath{\alpha},p)^{20}\mathrm{Ne}$ reaction rate was also calculated for the first time using resonance parameters for 12 energy levels.

A cascaded hybrid phase-locked loop (PLL) fabricated in a 65-nm CMOS process consumes 21 mW and occupies 0.4 mm2. An all-digital PLL (ADPLL) with piecewise linear calibrated hierarchical time-to-digital converter is proposed to achieve a wide operation range, and a charge-pump PLL (CPPLL) with an auxiliary (AUX) charge-pump for low current mismatch is cascaded to filter out the ADPLL output noise. The ADPLL achieves low long-term jitter regardless of the leakage current, and the CPPLL realizes low short-term jitter using a self-biased technique and the AUX charge pump. A phase-selectable divider is also proposed to divide the clock frequency while keeping the relative phase difference constant. The measured peak-to-peak short-term and long-term jitters at an output frequency of 315 MHz are 40 and 70 pspp, respectively, with a multiplication factor of 1024.

We propose a novel modulation profile for a spread spectrum clock generator (SSCG). The proposed piecewise linear (PWL) modulation profile significantly reduces electromagnetic interference with a simple implementation. Two SSCGs with two- and three-slope-PWL modulation profiles are used. Both SSCGs consist of the proposed spread spectrum control profile generator and a phase-locked loop that includes a high-resolution fractional divider to reduce quantization noise from a delta-sigma modulator. The SSCG with the two-slope-PWL modulation profile was fabricated in a 0.18 μm 1P4M CMOS technology. The measured peak power reduction level of the two-slope-PWL modulation profile is 14.2 dB with 5000 ppm down spreading at 1.5 GHz. The SSCG occupies an active area of 0.49 mm2 and consumes 40 mW of power at 1.5 GHz. The SSCG with the three-slope-PWL modulation profile was fabricated in a 0.13 μm 1P6M CMOS technology. The measured peak power reduction level of the three-slope-PWL modulation profile is 10.3 and 10.52 dB with 5000 ppm down spreading at 162 and 270 MHz, respectively. The SSCG occupies an active area of 0.096 mm2 and dissipates 1 mW of power at 270 MHz.

When a neutron star accretes hydrogen and helium from the outer layers of its companion star, thermonuclear burning enables the α p-process as a break out mechanism from the hot CNO cycle. Model calculations predict ( α , p) reaction rates significantly affect both the light curves and elemental abundances in the burst ashes. The Jet Experiments in Nuclear Structure and Astrophysics (JENSA) gas jet target enables the direct measurement of previously inaccessible ( α ,p) reactions with radioactive beams provided by the rare isotope re-accelerator ReA3 at the National Superconducting Cyclotron Laboratory (NSCL), USA. JENSA is going to be the main target for the Recoil Separator for Capture Reactions (SECAR) at the Facility for Rare Isotope Beams (FRIB). Commissioning of JENSA and first experiments at Oak Ridge National Laboratory (ORNL) showed a highly localized, pure gas target with a density of ∼10 19 atoms per square centimeter. Preliminary results are presented from the first direct cross section measurement of the 34 Ar( α , p) 37 K reaction at NSCL.

The 23 Al(p, γ)24 Si stellar reaction rate has a significant impact on the light-curve emitted in X-ray bursts. Theoretical calculations show that the reaction rate is mainly determined by the properties of direct capture as well as low-lying 2+ states and a possible 4+ state in 24 Si. Currently, there is little experimental information on the properties of these states.In this proceeding we will present a new experimental study to investigate this reaction, using the surrogate reaction 23 Al(d,n) at 47 AMeV at the National Superconducting Cyclotron Laboratory (NSCL). We will discuss our new experimental setup which allows us to use full kinematics employing the Gamma-Ray Energy Tracking In-beam Nuclear Array (GRETINA) to detect the γ-rays following the de-excitation of excited states of the reaction products and the Low Energy Neutron Detector Array (LENDA) to detect the recoiling neutrons. The S800 was used for identification of the 24 Si recoils. As a proof of principle to show the feasibility of this concept the Q-value spectrum of 22 Mg(d,n)23 Al is reconstructed.

Novel program and read schemes are presented to break barriers in scaling of NAND flash memory such as threshold voltage endurance from floating gate interference, and charge loss tolerance. To enhance threshold voltage endurance and charge loss tolerance, we introduced three schemes; MSB Re-PGM scheme, Moving Read scheme and Adaptive Code Selection scheme. Using the MSB Re-PGM scheme, threshold voltage distribution width is improved about 200 mV. The PGM throughput is enhanced from 1500 μs to 1250 μs. With the Moving Read scheme about half order of UBER is improved with 10 bit ECC. Also, Adaptive Code Selection scheme are used to decrease a current consumption. There is 5.5% current reduction. With these techniques, 32-Gb MLC NAND flash memory has been fabricated using a 32 nm CMOS process technology. Its program throughput reaches 13.0 MB/s at a multi-plane program operation with cache operation keeping a desirable threshold voltage distribution.

The $^{24}$Mg($p$, $\alpha$)$^{21}$Na reaction was measured at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory in order to better constrain spins and parities of energy levels in $^{21}$Na for the astrophysically important $^{17}$F($\alpha, p$)$^{20}$Ne reaction rate calculation. 31 MeV proton beams from the 25-MV tandem accelerator and enriched $^{24}$Mg solid targets were used. Recoiling $^{4}$He particles from the $^{24}$Mg($p$, $\alpha$)$^{21}$Na reaction were detected by a highly segmented silicon detector array which measured the yields of $^{4}$He particles over a range of angles simultaneously. A new level at 6661 $\pm$ 5 keV was observed in the present work. The extracted angular distributions for the first four levels of $^{21}$Na and Distorted Wave Born Approximation (DWBA) calculations were compared to verify and extract angular momentum transfer., Comment: 11 pages, 6 figures, proceedings of the 18th International Conference on Accelerators and Beam Utilization (ICABU2014)

This paper presents a 64Gb MLC NAND-Flash memory fabricated with 16nm CMOS process technology to achieve high density and as small as 93.4mm2 die area. The chip consists of two planes of 1072 blocks each. A block consists of a string with 128 cells and a page size with 16KB and spare area for error-correction coding (ECC), totaling 4MB of capacity. The chip supports negative-level wordline drivability to increase cell Vth margin.

The best examples of halo nuclei, exotic systems with a diffuse nuclear cloud surrounding a tightly-bound core, are found in the light, neutron-rich region, where the halo neutrons experience only weak binding and a weak, or no, potential barrier. Modern direct reaction measurement techniques provide powerful probes of the structure of exotic nuclei. Despite more than four decades of these studies on the benchmark one-neutron halo nucleus Be-11, the spectroscopic factors for the two bound states remain poorly constrained. In the present work, the Be-10(d,p) reaction has been used in inverse kinematics at four beam energies to study the structure of Be-11. The spectroscopic factors extracted using the adiabatic model, were found to be consistent across the four measurements, and were largely insensitive to the optical potential used. The extracted spectroscopic factor for a neutron in a nlj = 2s1/2 state coupled to the ground state of Be-10 is 0.71(5). For the first excited state at 0.32 MeV, a spectroscopic factor of 0.62(4) is found for the halo neutron in a 1p1/2 state., 5 pages, 4 figures

As NAND flash memory market grows rapidly in various application such as USB devices, MP3 players, SSD, cellular phone, cameras, there is a strong requirement of high density and low cost devices. Two different approaches studied to meet these requirements are increasing data per cell and scaling down. 3b/cell or 4b/cell NAND flash memories were introduced as an effective way to lower cost [1,2]. However, these devices suffer from significant program performance degradation since tighter Vth distribution is required. On the other hand, scaling down can be a candidate to achieve low cost while maintaining high program performance even though there are several hurdles to overcome such as floating gate (FG) coupling and charge retention [3].

An ADPLL with a piecewise linear calibrated hierarchical TDC is proposed to achieve a wide range of operation and a CPPLL is cascaded to filter out 1/f noise. A phase selectable divider is also proposed to divide the clock frequency while keeping the relative phase difference of output same as that of input. The cascaded hybrid PLL fabricated in 65nm CMOS process burns 17mW and occupies 0.4mm2. The measured jitters are 1.1ns pp and 223.6ps rms , respectively with a multiplication factor of 1,024.

A spread spectrum clock generator is implemented in a 0.18 mum CMOS process employing the proposed piecewise linear modulation profile to significantly reduce EMI with a simple implementation. A high resolution fractional divider to reduce quantization noise from the modulation is proposed as well. A peak power reduction level of 14.2 dB with 5000 ppm down spreading and 27.88 pspp of jitter in the SSCG without modulation are measured.

A high-density supersonic gas-jet target named JENSA (Jet Experiments in Nuclear Structure and Astrophysics) has been constructed and commissioned at Oak Ridge National Laboratory. The target creates a localized (∼ 4 mm wide) thick (∼10 19 atoms/cm2) concentration of gaseous atoms (H, He, N, etc...) that are suitable for use in high-resolution experiments with radioactive beams. The interaction point of the beam with the gas-jet target is surrounded by silicon strip detectors from the SuperORRUBA (Oak Ridge Rutgers University Barrel Array) to detect reaction products with good energy (∼30 keV) and angular resolution (∼1 degree). Initial experiments are discussed along with plans for future use at Michigan State University.