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The ongoing digitalisation of the learning processes has both opportunities and obstacles for the educational attaintment of students in STEM subjects. In this paper, we summarise student experiences with digitalisation during the COVID-19 pandemic and provide recommendations for how to improve teaching methods os STEM education. The research was conducted through focus groups in a workshop format at 15 European STEM universities across 8 different countries obtaining 147 responses from students. This paper also aims to analyse how the digital competency of both students and professors has been impacting the effectivenessof new teaching methods and education tools during online classes since the start of the pandemic. Students have a variety of needs, with some students preferring the flexibility and anonymity online work gives them, while others thrive better when they are face to face with instructors and dislike the limitations that exist in virtual communication. In addition, we looked at how students view changes in the evaluation of projects and tests that have occcurred to prevent cheating. The results show the relevance of digital education and which aspects of it need to be developed further. The paper further explores possible solutions for the issues identified in this research, including learning, methodological and skill development aspects. Overall, we propose hybrid classrooms where students have the choice to explore which method of learning best fits them and how professors can support them to ensure the best educational outcome.

Lifetimes or lifetime limits of a small number of excited states of the sulfur isotopes with mass numbers A=35, 36, 37, and 38 have been measured using the differential recoil-distance method. The isotopes of sulfur were populated in binary grazing reactions initiated by a beam of 36S ions of energy 225 MeV incident on a thin 208Pb target which was mounted in the Cologne plunger apparatus. The combination of the PRISMA magnetic spectrometer and an early implementation of the AGATA γ-ray tracking array was used to detect γ rays in coincidence with projectile-like nuclear species. Lifetime measurements of populated states were measured within the range from about 1 to 100 ps. The number of states for which lifetime measurements or lifetime limits were possible was limited by statistics. For 35S, the lifetime was determined for the first 1/2+ state at 1572 keV ; the result is compared with a previous published lifetime value. The lifetime of the 3− state of 36S at 4193 keV was determined and compared with earlier measurements. No previous lifetime information exists for the (6+) state at 6690 keV ; a lifetime measurement with large associated error was made in the present work. For 37S, the states for which lifetime limits were established were those at 646 keV with Jπ=3/2− and at 2776 keV with Jπ=11/2− ; there are no previously published lifetime values for excited states of 37S. Finally, a lifetime limit was established for the Jπ=(6+) state of 38S at 3675 keV ; no lifetime information exists for this state in the literature. Measured lifetime values were compared with the results of state-of-the-art shell-model calculations based on the PSDPF, SDPF-U, and FSU effective interactions. In addition, nuclear magnetic-dipole and electric-quadrupole moments, branching ratios, mixing ratios, and electromagnetic transition rates, where available, have been compared with shell-model values. The current work suffers from poor statistics ; nevertheless, lifetime values and limits have been possible, allowing a useful discussion of the ability of state-of-the-art shell-model calculations to reproduce the experimental results.

Lifetimes or lifetime limits of a small number of excited states of the sulfur isotopes with mass numbers A=35, 36, 37, and 38 have been measured using the differential recoil-distance method. The isotopes of sulfur were populated in binary grazing reactions initiated by a beam of 36S ions of energy 225 MeV incident on a thin 208Pb target which was mounted in the Cologne plunger apparatus. The combination of the PRISMA magnetic spectrometer and an early implementation of the AGATA γ-ray tracking array was used to detect γ rays in coincidence with projectile-like nuclear species. Lifetime measurements of populated states were measured within the range from about 1 to 100 ps. The number of states for which lifetime measurements or lifetime limits were possible was limited by statistics. For 35S, the lifetime was determined for the first 1/2+ state at 1572 keV; the result is compared with a previous published lifetime value. The lifetime of the 3− state of 36S at 4193 keV was determined and compared with earlier measurements. No previous lifetime information exists for the (6+) state at 6690 keV; a lifetime measurement with large associated error was made in the present work. For 37S, the states for which lifetime limits were established were those at 646 keV with Jπ=3/2− and at 2776 keV with Jπ=11/2−; there are no previously published lifetime values for excited states of 37S. Finally, a lifetime limit was established for the Jπ=(6+) state of 38S at 3675 keV; no lifetime information exists for this state in the literature. Measured lifetime values were compared with the results of state-of-the-art shell-model calculations based on the PSDPF, SDPF-U, and FSU effective interactions. In addition, nuclear magnetic-dipole and electric-quadrupole moments, branching ratios, mixing ratios, and electromagnetic transition rates, where available, have been compared with shell-model values. The current work suffers from poor statistics; nevertheless, lifetime values and limits have been possible, allowing a useful discussion of the ability of state-of-the-art shell-model calculations to reproduce the experimental results.

Lifetimes of excited states of the phosphorus isotopes 1533,34,35,36P have been measured by using the differential recoil-distance method. The isotopes of phosphorus were populated in binary grazing reactions initiated by a beam of S36 ions of energy 225 MeV incident on a thin Pb208 target mounted in the Cologne plunger apparatus. The combination of the PRISMA magnetic spectrometer and an early implementation of the AGATA γ-ray tracking array was used to detect γ rays in coincidence with projectile-like nuclear species. Lifetime measurements of populated states were made within the range from about 1 to 100 ps. The number of states for which lifetime measurements were possible was limited by statistics. For P33, lifetime limits were determined for the first 3/2+ and 5/2+ states at 1431 and 1848 keV, respectively; the results are compared with previous published lifetime values. The lifetime of the first 2+ state of P34 at 429 keV was determined and compared with earlier measurements. For P35, the states for which lifetimes, or lifetime limits, were determined were those at 2386, 3860, 4101, and 4493 keV, with Jπ values of 3/2+, 5/2+, 7/21−, and 7/22−, respectively. There have been no previous published lifetimes for states in this nucleus. A lifetime was measured for the stretched π(1f7/2)⊗ν(1f7/2)Jπ=(7+) state of P36 at 5212 keV and a lifetime limit was established for the stretched π(1d3/2)⊗ν(1f7/2)Jπ=(5−) state at 2030 keV. There are no previously published lifetimes for states of P36. Measured lifetime values were compared with the results of state-of-the-art shell-model calculations based on the PSDPF effective interaction. In addition, measured branching ratios, published mixing ratios, and electromagnetic transition rates, where available, have been compared with shell-model values. In general, there is good agreement between experiment and the shell model; however there is evidence that the shell-model values of the M1 transition rates for the 3/21+→1/2+ (ground state) and 5/21+→3/21+ transitions in P33 underestimate the experimental values by a factor between 5 and 10. In P35 there are some disagreements between experimental and shell-model values of branching ratios for the first and second excited 7/2− states. In particular, there is a serious disagreement for the decay characteristics of the second 7/2− state at 4493 keV, for which the shell-model counterpart lies at 4754 keV. In this case, the shell-model competing electromagnetic decay branches are dominated by E1 and M1 transitions.

International audience; Lifetimes of excited states of the phosphorus isotopes 1533,34,35,36P have been measured by using the differential recoil-distance method. The isotopes of phosphorus were populated in binary grazing reactions initiated by a beam of S36 ions of energy 225 MeV incident on a thin Pb208 target mounted in the Cologne plunger apparatus. The combination of the PRISMA magnetic spectrometer and an early implementation of the AGATA γ-ray tracking array was used to detect γ rays in coincidence with projectile-like nuclear species. Lifetime measurements of populated states were made within the range from about 1 to 100 ps. The number of states for which lifetime measurements were possible was limited by statistics. For P33, lifetime limits were determined for the first 3/2+ and 5/2+ states at 1431 and 1848 keV, respectively; the results are compared with previous published lifetime values. The lifetime of the first 2+ state of P34 at 429 keV was determined and compared with earlier measurements. For P35, the states for which lifetimes, or lifetime limits, were determined were those at 2386, 3860, 4101, and 4493 keV, with Jπ values of 3/2+, 5/2+, 7/21−, and 7/22−, respectively. There have been no previous published lifetimes for states in this nucleus. A lifetime was measured for the stretched π(1f7/2)⊗ν(1f7/2)Jπ=(7+) state of P36 at 5212 keV and a lifetime limit was established for the stretched π(1d3/2)⊗ν(1f7/2)Jπ=(5−) state at 2030 keV. There are no previously published lifetimes for states of P36. Measured lifetime values were compared with the results of state-of-the-art shell-model calculations based on the PSDPF effective interaction. In addition, measured branching ratios, published mixing ratios, and electromagnetic transition rates, where available, have been compared with shell-model values. In general, there is good agreement between experiment and the shell model; however there is evidence that the shell-model values of the M1 transition rates for the 3/21+→1/2+ (ground state) and 5/21+→3/21+ transitions in P33 underestimate the experimental values by a factor between 5 and 10. In P35 there are some disagreements between experimental and shell-model values of branching ratios for the first and second excited 7/2− states. In particular, there is a serious disagreement for the decay characteristics of the second 7/2− state at 4493 keV, for which the shell-model counterpart lies at 4754 keV. In this case, the shell-model competing electromagnetic decay branches are dominated by E1 and M1 transitions.

Lifetimes of excited states of the phosphorus isotopes 33 , 34 , 35 , 36 15 P have been measured by using the differential recoil-distance method. The isotopes of phosphorus were populated in binary grazing reactions initiated by a beam of 36 S ions of energy 225 MeV incident on a thin 208 Pb target mounted in the Cologne plunger apparatus. The combination of the PRISMA magnetic spectrometer and an early implementation of the AGATA γ -ray tracking array was used to detect γ rays in coincidence with projectile-like nuclear species. Lifetime measurements of populated states were made within the range from about 1 to 100 ps. The number of states for which lifetime measurements were possible was limited by statistics. For 33 P , lifetime limits were determined for the first 3/2+ and 5/2+ states at 1431 and 1848 keV, respectively; the results are compared with previous published lifetime values. The lifetime of the first 2+ state of 34 P at 429 keV was determined and compared with earlier measurements. For 35 P , the states for which lifetimes, or lifetime limits, were determined were those at 2386, 3860, 4101, and 4493 keV, with Jπ values of 3/2+, 5/2+, 7/2− 1 , and 7/2− 2 , respectively. There have been no previous published lifetimes for states in this nucleus. A lifetime was measured for the stretched π ( 1 f 7 / 2 ) ⊗ ν ( 1 f 7 / 2 ) J π = ( 7 + ) state of 36 P at 5212 keV and a lifetime limit was established for the stretched π ( 1 d 3 / 2 ) ⊗ ν ( 1 f 7 / 2 ) J π = ( 5 − ) state at 2030 keV. There are no previously published lifetimes for states of 36 P . Measured lifetime values were compared with the results of state-of-the-art shell-model calculations based on the PSDPF effective interaction. In addition, measured branching ratios, published mixing ratios, and electromagnetic transition rates, where available, have been compared with shell-model values. In general, there is good agreement between experiment and the shell model; however there is evidence that the shell-model values of the M1 transition rates for the 3/2+1→ 1 / 2 + (ground state) and 5/2+1→ 3 / 2 + 1 transitions in 33 P underestimate the experimental values by a factor between 5 and 10. In 35 P there are some disagreements between experimental and shell-model values of branching ratios for the first and second excited 7/2− states. In particular, there is a serious disagreement for the decay characteristics of the second 7/2− state at 4493 keV, for which the shell-model counterpart lies at 4754 keV. In this case, the shell-model competing electromagnetic decay branches are dominated by E1 and M1 transitions.

High-spin terminating bands in heavy nuclei were first identified in nuclei around Er-158(90). While examples of terminating states have been identified in a number of erbium isotopes, almost nothing is known about the states lying beyond band termination. In the present work, the high-spin structure of Er-156,Er-157,Er-158 has been studied using the Gammasphere spectrometer. The subject of triaxial superdeformation and 'wobbling' modes in Lu nuclei has rightly attracted a great deal of attention. Very recently four strongly or superdeformed (SD) sequences have been observed in Hf-174, and cranking calculations using the Ultimate Cranker code predict that such structures may have significant triaxial deformation. We have performed two experiments in an attempt to verify the possible triaxial nature of these bands. A lifetime measurement was performed to confirm the large (and similar) deformation of the bands. In addition, a high-statistics, thin-target experiment took place to search for linking transitions between the SD bands, possible wobbling modes, and new SD band structures.

5th International Workshop on Nuclear Fission and Fission Product Spectroscopy (FISSION) -- MAY 28-31, 2013 -- Caen, FRANCE, WOS: 000342384500002, Lifetimes of first 4(+) and 6(+) states have been measured in neutron-rich isotopes of Zr, Mo, Ru and Pd using the recoil distance Doppler shift method at GANIL. The nuclei were produced through a fusion-fission reaction in inverse kinematics. The fission fragments were fully identified in the large-acceptance VAMOS spectrometer and gamma -rays were detected in coincidence with the EXOGAM germanium array. Lifetimes of excited states in the range of 1-100 ps were measured with the Cologne plunger. Preliminary lifetime results are presented as well as a discussion on the evolution of the collectivity in this region., ILL, CEA DSM & DAM, CNRS IN2P3, ENSICAEN, GANIL, Scientific and Technological Council of Turkey [210T043], S. Erturk acknowledges the Scientific and Technological Council of Turkey for their support with project number 210T043.

High-spin terminating bands in heavy nuclei were first identified in nuclei around Er-158(90). While examples of special terminating states have been identified in a number of erbium isotopes, almost nothing is known about the states lying beyond band termination. In the present work the high-spin structure of Er-157 has been studied using the Gammasphere spectrometer. The subject of triaxial superdeformation and 'wobbling' modes in Lu nuclei has rightly attracted a great deal of attention. Very recently, four strongly or superdeformed (SD) sequences have been observed in Hf-174 and ultimate cranker calculations predict, such structures may have significant triaxial deformation. We have performed two experiments in an attempt to verify the possible triaxial nature of these bands. A lifetime measurement was performed to confirm the large (and similar) deformation of the bands. In addition, a high-statistics, thin-target experiment was run to search for linking transitions between the SD bands and possible wobbling modes.

WOS: 000301813500009, A study of the dimensions and performance of a single detector of the future neutron detector array NEDA was performed by means of Monte Carlo simulations, using GEANT4. Two different liquid scintillators were evaluated: the hydrogen based BC501A and the deuterated BC537. The efficiency and the probability that one neutron will trigger a signal in more than one detector were investigated as a function of the detector size. The simulations were validated comparing the results to experimental measurements performed with two existing neutron detectors, with different geometries, based on the liquid scintillator BC501. (C) 2012 Elsevier B.V. All rights reserved., Polish Ministry of Science and Higher Education [N N202 073935]; Swedish Research Council; European Union [212692]; LEA COPIGAL; COPIN-IN2P3; Warsaw University of Technology; MICINN, Spain [AIC10-D-000568]; INFN, Italy [AIC10-D-000568]; MICINN; Generalitat Valenciana, Spain [FPA2008-06419, PROMETEO/2010/101], This work was partly supported by the Polish Ministry of Science and Higher Education, grant no. N N202 073935, by the Swedish Research Council, by the European Union within the Spiral2 Preparatory Phase project (7t Framework Programme, project no. 212692), by the LEA COPIGAL and COPIN-IN2P3 collaborations, and within the framework of the European Social Fund through the Warsaw University of Technology Development Programme, realised by the Center for Advanced Studies. A. Gadea and E. Farnea acknowledge the support of MICINN, Spain, and INFN, Italy, through the AIC10-D-000568 bilateral action. A. Gadea and T. Huyuk have been partially supported by the MICINN and Generalitat Valenciana, Spain, under grants FPA2008-06419 and PROMETEO/2010/101. We acknowledge help of colleagues from the National Centre for Nuclear Research at Swierk, Poland, in particular of L. Swiderski, and thank them for providing one of the detectors and electronics. Valuable discussions with J.L. Tain, D. Cano-Ott and A. Algora are also acknowledged.

International audience; This board will be part of the upgrade for the new electronics for the EXOGAM2 (HP-Ge detector array) and NEDA (BC501A-based neutron detector array), therefore it was necessary to deal with the problem of providing a sampling card with high resolution for new gamma spectroscopy experiments while sampling at very high rates, with a broad bandwidth in order to preserve the shape for further analysis. Pulse shape analysis is of paramount importance in neutron detectors, such as NEDA, based on scintillators that are sensitive to γ-rays as well. High resolution and high speed are often two parameters which conform a trade-off and it is hard to achieve both simultaneously. The aforementioned constraints and the urge of building new sampling electronics to improve the signal analysis in nuclear physics experiments, led to the development of this FADC mezzanine This involves sampling rates up to 250 Msps preserving a high resolution of 11.3 effective bits in order to satisfy the experiment demands. In this work is described the design and the test bench proposed for a proper high speed ADC characterization system and the results obtained up to now.

Objective: Since abdominal adiposity has been associated with increased risk for chronic diseases, valid and low cost methods to estimate it are needed for clinical and research purposes. The aim of the current study was to develop and validate, using dual-energy x-ray absorptiometry (DXA) as reference method, a model that estimates abdominal fat mass percentage (AFM%) in white postmenopausal women based on simple and easy-to-apply anthropometric measurements. An additional aim was to validate an abdominal bioelectrical impedance analyzer (ViScan) for estimating waist circumference (WC) and AFM% in this group. Methods: Ninety-one postmenopausal women (mean age, 61.5 y) with body mass index ranging from 20.9 to 42 kg/m 2 were randomly divided into one training set (n = 60) and one testing set (n = 31) to develop and validate a model based on anthropometric measurements estimating abdominal fat mass. Furthermore, in all 91 participants, ViScan estimations of WC and AFM% were validated against tape measurement and DXA results. Results: The model developed was AFM% = 4.496 + (0.318 � WC) + 0.342 � suprailiac skinfold (r =0 .834,P G 0.0001). The model had no significant bias (0.25%) and T7.5% limits of agreement. ViScan significantly overestimated WC by 7.04 cm and estimated AFM% with no significant bias (j0.13%) and T7.6% limits of agreement. Conclusions: Both the model and ViScan are equally valid against DXA in estimating AFM%. However, ViScan is not valid in estimating WC in white postmenopausal women.

High-spin states in 187Pt have been studied by means of γ-ray spectroscopy techniques. Known bands have been significantly extended and new bands have been found. The band structures are discussed in the framework of the cranking model and negative-parity states are compared with calculations performed with a semi-microscopic axial-rotor plus one-quasiparticle coupling model. Shape coexistence is observed from low excitation energy.

2012 18th IEEE-NPSS Real Time Conference, RT 2012 -- 9 June 2012 through 15 June 2012 -- Berkeley, CA -- 95754 This board will be part of the upgrade for the new electronics for the EXOGAM2 (HP-Ge detector array) and NEDA (BC501A-based neutron detector array), therefore it was necessary to deal with the problem of providing a sampling card with high resolution for new gamma spectroscopy experiments while sampling at very high rates, with a broad bandwidth in order to preserve the shape for further analysis. Pulse shape analysis is of paramount importance in neutron detectors, such as NEDA, based on scintillators that are sensitive to ?-rays as well. High resolution and high speed are often two parameters which conform a trade-off and it is hard to achieve both simultaneously. The aforementioned constraints and the urge of building new sampling electronics to improve the signal analysis in nuclear physics experiments, led to the development of this FADC mezzanine This involves sampling rates up to 250 Msps preserving a high resolution of 11.3 effective bits in order to satisfy the experiment demands. In this work is described the design and the test bench proposed for a proper high speed ADC characterization system and the results obtained up to now. © 2012 IEEE.

The Cd-114(Ca-48, 6n gamma) reaction at 215 MeV has been investigated using the Gammasphere spectrometer to study the high-spin structure of the nucleus Er-156(68)88. Many new transitions have been established along with 68 definitive spin-parity level assignments from a high-fold angular-distribution analysis. In addition, absolute B(M 1) and B(E 1) strengths have been inferred from measured gamma-ray branching ratios. Strong B(E 1) strength (10(-3) W.u.) is discussed in terms of possible octupole collectivity at low spin. At high spin, this nucleus undergoes a Coriolis-induced shape transition from a prolate state of collective rotation to a noncollective, triaxial-oblate configuration. The yrast positive-parity structure ultimately terminates in an energetically favored oblate state at I-pi = 42(+). Several weak high-energy gamma-ray transitions have been discovered that feed this favored state. State-of-the-art cranked Nilsson-Strutinsky calculations are used to interpret the high-spin behavior of Er-156 and comparisons are made with other N = 88 isotones. (Less)

The N ∼ 90 region of the nuclear chart has featured prominently as the spectroscopy of nuclei at extreme spin has progressed. This talk will present recent discoveries from investigations of high spin behavior in the N ∼ 90 Er, Tm and Yb nuclei utilizing the Gammasphere gamma-ray spectrometer. In particular it will include discussion of the beautiful shape evolution and coexistence observed in these nuclei along with the identification of a remarkable new family of band structures. The latter are very weakly populated rotational sequences with high moment of inertia that bypass the classic terminating configurations near spin 40-50h{stroke}, marking a return to collectivity that extends discrete γ-ray spectroscopy to well over 60h{stroke}. Establishing the nature of the yrast states in these nuclei beyond the oblate band-termination states has been a major goal for the past two decades. Cranking calculations suggest that these new structures most likely represent stable triaxial strongly deformed bands that lie in a valley of favored shell energy in deformation and particle-number space.

A new frontier of discrete-line gamma-ray spectroscopy at ultrahigh spin has been opened in the rare-earth nuclei (157,158) Er. Four rotational structures, displaying high moments of inertia, have been identified, which extend up to spin approximately 65 variant Planck's over 2pi and bypass the band-terminating states in these nuclei which occur at approximately 45 variant Planck's over 2pi. Cranked Nilsson-Strutinsky calculations suggest that these structures arise from well-deformed triaxial configurations that lie in a valley of favored shell energy which also includes the triaxial strongly deformed bands in (161-167) Lu.

High-spin states in 187Pt have been studied by means of γ-ray spectroscopy techniques. Known bands have been significantly extended and new bands have been found. The band structures are briefly discussed. Fil: Cardona, Maria Angelica. Comisión Nacional de Energía Atómica; Argentina Fil: Hojman, Daniel Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; Argentina Fil: Aguilar, A.. Florida State University; Estados Unidos Fil: Cluff, W.T.. Florida State University; Estados Unidos Fil: Hinners, T.. Florida State University; Estados Unidos Fil: Hoffman, C.R.. Florida State University; Estados Unidos Fil: Lagergren, K.. Florida State University; Estados Unidos Fil: Lee, S.. Florida State University; Estados Unidos Fil: Perry, M.. Florida State University; Estados Unidos Fil: Pipidis, A.. Florida State University; Estados Unidos Fil: Riley, M.A.. Florida State University; Estados Unidos Fil: Tabor, S.L.. Florida State University; Estados Unidos Fil: Tripathi, V.. Florida State University; Estados Unidos

A new frontier of discrete-line gamma-ray spectroscopy at ultrahigh spin has been opened in the rare-earth nuclei (157,158) Er. Four rotational structures, displaying high moments of inertia, have been identified, which extend up to spin approximately 65 variant Planck's over 2pi and bypass the band-terminating states in these nuclei which occur at approximately 45 variant Planck's over 2pi. Cranked Nilsson-Strutinsky calculations suggest that these structures arise from well-deformed triaxial configurations that lie in a valley of favored shell energy which also includes the triaxial strongly deformed bands in (161-167) Lu.

The high-spin structure of Er-157 has been greatly expanded using the Gammasphere spectrometer to investigate the Cd-114(Ca-48,5n) reaction at 215 MeV. Many new transitions have been placed in a greatly augmented level scheme up to spin 40h with many collective rotational sequences established. With increasing angular momentum, this nucleus undergoes a Coriolis-induced shape transition from a deformed state of collective rotation to a noncollective configuration. This transition manifests itself as favored band termination near I=45h in three rotational structures. Many weakly populated states lying at high excitation energy that decay into the terminating states have been discovered. Cranked-Nilsson-Strutinsky calculations suggest that the levels that feed the terminating states arise from weakly collective configurations that break the Z=64 semimagic core. (Less)

The reaction 13C(alpha,n) is considered to be the main source of neutrons for the s process in asymptotic giant branch stars. At low energies, the cross section is dominated by the 1/2+ 6.356 MeV subthreshold resonance in (17)O whose contribution at stellar temperatures is uncertain by a factor of 10. In this work, we performed the most precise determination of the low-energy astrophysical S factor using the indirect asymptotic normalization (ANC) technique. The alpha-particle ANC for the subthreshold state has been measured using the sub-Coulomb alpha-transfer reaction ((6)Li,d). Using the determined ANC, we calculated S(0), which turns out to be an order of magnitude smaller than in the nuclear astrophysics compilation of reaction rates.

The $^{14}\mathrm{C}$($^{14}\mathrm{C}$, d) reaction at 22 MeV was used to study ${T}_{z}=2$ $^{26}\mathrm{Na}$. Charged particles were detected with a Si detector telescope at ${0}^{\ifmmode^\circ\else\textdegree\fi{}}$, and \ensuremath{\gamma} transitions in coincidence were detected with an array of three Compton-suppressed ``clover'' detectors and seven Compton-suppressed single Ge crystals. The Deuteron-\ensuremath{\gamma} and $d\text{\ensuremath{-}}\ensuremath{\gamma}\text{\ensuremath{-}}\ensuremath{\gamma}$ coincidence data were analyzed to study the structure of $^{26}\mathrm{Na}$. New levels were found, and precise energies and \ensuremath{\gamma}-decay patterns were determined for many states previously observed in charge-exchange reactions. Candidates were observed for the ${1}^{+}$ state missing in \ensuremath{\beta} decay. Mixing ratios were determined for some \ensuremath{\gamma} transitions from angular distribution information. There is reasonable agreement with the model based on the universal $s\text{\ensuremath{-}}d$ shell (USD) interaction.

Significant extensions to the high-spin excitation spectrum of the N = 91, 92, 93 isotopes Dy-157,Dy-158,Dy-159 have been achieved using the high-efficiency gamma-ray spectrometers Euroball and Gammasphere. These nuclei were populated via weak 3n or alpha xn exit channels in fusion evaporation reactions. In Dy-157, the yrast band has been extended to I-pi = (2)/(101+) (tentatively to (2)/(105+)) with four sideband structures (two of which are new) observed in the 35-50h spin range. In Dy-158, three bands have been extended to 42(+)(44(+)),40(-), and 41(-)(43(-)), whereas in Dy-159 the yrast band is observed to (2)/(81+) ((2)/(85+)). The high-spin behavior and band crossing systematics of the Dy isotopes and of the neighboring N = 91, 92, and 93 isotones are discussed in terms of rotational alignments and shape transitions. Cranked Nilsson-Strutinsky calculations without pairing have been performed for detailed comparisons with the very high-spin states observed in Dy-157.

Significant extensions to the high-spin excitation spectrum of the N=91, 92, 93 isotopes Dy157,158,159 have been achieved using the high-efficiency γ-ray spectrometers Euroball and Gammasphere. These nuclei were populated via weak 3n or αxn exit channels in fusion evaporation reactions. In Dy157, the yrast band has been extended to Iπ=1012+ (tentatively to 1052+) with four sideband structures (two of which are new) observed in the 35-50 spin range. In Dy158, three bands have been extended to 42+(44+),40-, and 41-(43-), whereas in Dy159 the yrast band is observed to 812+(852+). The high-spin behavior and band crossing systematics of the Dy isotopes and of the neighboring N = 91, 92, and 93 isotones are discussed in terms of rotational alignments and shape transitions. Cranked Nilsson-Strutinsky calculations without pairing have been performed for detailed comparisons with the very high-spin states observed in Dy157.

The angular-momentum induced transition from a deformed state of collective rotation to a noncollective configuration has been studied. In Er-157 this transition manifests itself as favored band termination near I=45 (h) over bar. The feeding of these band terminating states has been investigated for the first time using the Gammasphere spectrometer. Many weakly populated states lying at high excitation energy that decay into these special states have been discovered. Cranked Nilsson-Strutinsky calculations suggest that these states arise from weakly collective "core-breaking" configurations.

The ${}^{14}\mathrm{C}{(}^{14}\mathrm{C},\ensuremath{\alpha})$ reaction at 22 MeV was used to study $T=2$ ${}^{24}\mathrm{Ne}.$ Charged particles were detected with a Si detector telescope at $0\ifmmode^\circ\else\textdegree\fi{},$ and $\ensuremath{\gamma}$ transitions in coincidence were detected with an array of three Compton-suppressed ``clover'' detectors and seven Compton-suppressed single Ge crystals. The $\ensuremath{\alpha}\ensuremath{-}\ensuremath{\gamma}$ and $\ensuremath{\alpha}\ensuremath{-}\ensuremath{\gamma}\ensuremath{-}\ensuremath{\gamma}$ coincidence data were analyzed to study the structure of ${}^{24}\mathrm{Ne}.$ Twenty-two new $\ensuremath{\gamma}$ lines were assigned to 14 new levels. Angular distribution measurements provided spin assignments and restrictions to a number of levels. Likely candidates were found for the lowest ${5}^{+}$ and ${6}^{+}$ levels. All but one of the 12 states predicted to lie below 6 MeV by shell model calculations using the universal $s\ensuremath{-}d$ interaction were observed. The rms deviation in excitation energies among these is 190 keV, and there is a tendency for the observed levels to lie somewhat higher than the predicted ones. A comparison of the structure of ${}^{24}\mathrm{Ne}$ with its neighbors suggests a significant shell gap above the $\ensuremath{\nu}{d}_{5/2}$ orbital in agreement with the large ${d}_{5/2}\ensuremath{-}{s}_{1/2}$ gap implied by the effective single-particle energies in the universal $s\ensuremath{-}d$ shell model interaction.

Very high spin states $(I=50--60\ensuremath{\Elzxh})$ have been observed in the transitional nuclei ${}^{161}\mathrm{Er}$ and ${}^{162}\mathrm{Er}$ using the Euroball $\ensuremath{\gamma}$-ray spectrometer. In ${}^{161}\mathrm{Er},$ three bands are observed well above spin $50\ensuremath{\Elzxh}.$ In the positive parity, positive signature $(+,+\frac{1}{2})$ band a discontinuity in the regular rotational behavior occurs at ${\frac{109}{2}}^{+}$ and a splitting into two branches occurs at ${\frac{97}{2}}^{\ensuremath{-}}$ in the negative parity, positive signature $(\ensuremath{-},+\frac{1}{2})$ band. The $(\ensuremath{-},\ensuremath{-}\frac{1}{2})$ band continues in a regular fashion to ${\frac{115}{2}}^{\ensuremath{-}},$ tentatively $({\frac{119}{2}}^{\ensuremath{-}}).$ In ${}^{162}\mathrm{Er}$ the positive parity, even spin (+,0) yrast band is observed to continue smoothly up to ${58}^{+}$ ${(60}^{+})$ and the negative parity, even spin $(\ensuremath{-},0)$ and odd spin $(\ensuremath{-},1)$ bands are extended from ${30}^{\ensuremath{-}}$ to ${34}^{\ensuremath{-}}$ and from ${31}^{\ensuremath{-}}$ to ${47}^{\ensuremath{-}}$ ${(49}^{\ensuremath{-}}),$ respectively. The high spin experimental spectra are compared with both a simple model involving the occupation of specific single neutron states in the absence of neutron pair correlations and with more detailed cranked Nilsson-Strutinsky calculations in which both proton and neutron pairing correlations are neglected. The very high spin domain is found to comprise a series of unpaired rotational bands. Unpaired band crossings between bands with different neutron and proton configurations are identified in ${}^{161}\mathrm{Er}.$ There is no evidence for aligned oblate or terminating states being close to the yrast line in ${}^{161,162}\mathrm{Er}$ up to spin $\ensuremath{\approx}60\ensuremath{\Elzxh}$ in contrast to the lighter Er isotopes.