Search results for "Reaction"

Nuclear structure of 157Gd

2003

Abstract The energy levels of 157 Gd have been investigated using the (n,  γ ) and (n, n′ γ ) reactions. As a result of the analysis of the γ -ray spectra from 16 isolated neutron resonances, a level scheme with a complete set of levels with spins J =1/2, 3/2 has been established up to 1.86 MeV excitation energy. A part of the level scheme is interpreted in more detail on the basis of Coriolis and Δ N =2 coupled Nilsson configurations. Slightly different sets of shape parameters are deduced for negative- and positive-parity levels. A large excess of unassigned 1/2 and 3/2 levels evidently requires an explanation in terms of inclusion of new additional degrees of freedom.

Determination of nuclear spins of short-lived Rb and Cs isotopes by β radiation detected optical pumping

1978

Energy dependence of the $^{28}$Si($^{32}$S,$^{36}$Ar)$^{24}$Mg reaction between 90 and 103 MeV incident energy

1986

Abstract Angular distributions for the 28 Si( 32 S, 36 Ar) 24 Mg reaction have been measured from 90 to 103 MeV of incident lab energy, in steps of 0.5 MeV. The ground state, the 2 1 + level in each nucleus and the mutual excitation of both 2 1 + states have been resolved. The data have been analysed in the frame of finite range DWBA calculations. The deduced relative spectroscopic factors show good agreement with those predicted by the model of Chung and Wildenthal but are smaller than those deduced in other experiments.

Direct evidence of secondary recoiled nuclei from high energy protons

2008

The production of secondary recoiled particles from interactions between high energy protons and microelectronics devices was investigated. By using NAND Flash memories, we were able to directly obtain analog information on recoil characteristics. While our results qualitatively confirm the role of nuclear reactions, in particular of those with tungsten, a quantitative model based on Monte Carlo and device-level simulations cannot describe the observed results in terms of recoils from proton-W reactions. © 2006 IEEE.

The recoil transfer chamber—An interface to connect the physical preseparator TASCA with chemistry and counting setups

2011

Performing experiments with transactinide elements demands highly sensitive detection methods due to the extremely low production rates (one-atom-at-a-time conditions). Preseparation with a physical recoil separator is a powerful method to significantly reduce the background in experiments with sufficiently long-lived isotopes (t1/2≥0.5 s). In the last years, the new gas-filled TransActinide Separator and Chemistry Apparatus (TASCA) was installed and successfully commissioned at GSI. Here, we report on the design and performance of a Recoil Transfer Chamber (RTC) for TASCA—an interface to connect various chemistry and counting setups with the separator. Nuclear reaction products recoiling o…

Search for a 2-quasiparticle high-Kisomer inRf256

2011

The energies of 2-quasiparticle (2-qp) states in heavy shell-stabilized nuclei provide information on the single-particle states that are responsible for the stability of superheavy nuclei. We have calculated the energies of 2-qp states in {sup 256}Rf, which suggest that a long-lived, low-energy 8{sup -} isomer should exist. A search was conducted for this isomer through a calorimetric conversion electron signal, sandwiched in time between implantation of a {sup 256}Rf nucleus and its fission decay, all within the same pixel of a double-sided Si strip detector. A 17(5)-{mu}s isomer was identified. However, its low population, {approx}5(2)% that of the ground state instead of the expected {a…

Out-of-plane measurements of the fifth response function of the exclusive electronuclear response

1999

The first measurements of f{sub LT}{sup '}, known as the fifth response function, have been made for the {sup 2}H(e(vector sign),e{sup '}p) and {sup 12}C(e(vector sign),e{sup '}p) reactions. This response is directly related to the imaginary part of the interference between the transverse and longitudinal nuclear electromagnetic currents. Its observation requires longitudinally polarized electron beams and out-of-plane detection, the latter made possible by the newly developed out-of-plane spectrometer system. The initial measurements were made by using a 560-MeV polarized electron beam and quasielastic kinematics at Q{sup 2}=3.3 fm{sup -2}. The development of the methodology for out-of-pla…

Transition probabilities in negative parity bands of the 119I nucleus

2001

Abstract Lifetimes in four negative-parity bands of 119 I were measured using DSAM and RDM. 119 I nuclei were produced in the 109 Ag( 13 C,3n) reaction, γγ coincidences were collected using the NORDBALL array. RDDSA — a new method of RDM analysis — is described. This method allowed for the self-calibration of stopping power. From 31 measured lifetimes, 39 values of B (E2) were established. Calculations in the frame of the Core Quasi Particle Coupling (CQPC) model were focused on the problem of susceptibility of the nucleus to γ -deformation. It was established that nonaxial quadrupole deformation of 119 I plays on important role. The Wilets–Jean model of a γ -soft nucleus describes the 119 …

The role of the shape driving neutron orbital in 108Cd

1993

Abstract The nucleus 108Cd has been studied using a heavy-ion reaction and the NORDBALL multi-detector array. The yrast band has been extended to Ip = 24+, and nine quasi-rotational side bands have been identified. The n h 11 2 negative-parity orbital is found to play a dominant role both in the low-spin as well as in the high-spin structure of 108Cd. The first band crossing in the yrast band is caused by the h 11 2 neutrons. The 10+ state of the aligned n( h 11 2 ) 2 configuration decays strongly into a low-lying low-spin intruder-like positive-parity band. It is suggested that this intruder structure is dominated by a non-aligned n( h 11 2 ) 2 configuration. For the first time in this mas…

High-j bands in 173Ir

1991

Abstract High-spin states in rotational bands associated with the 11 2 − [505] , 1 2 − [541] and 1 2 + [660] Nilsson orbits have been observed in the previously unknown 173Ir nucleus using the 144Sm(32S,p2n) reaction at 163 MeV. The B(M1; I → I − 1)/B(E2; I → I −2) ratios have been extracted for the 11 2 − [505] band and compared with predictions of the semiempirical model by Donau and Frauendorf. The quasineutron band crossing frequencies and alignment gains are discussed in terms of the CSM model. Calculations for equilibrium deformations suggest different deformations for the three bands observed.