198 research outputs found
Excited States in 52Fe and the Origin of the Yrast Trap at I=12+
Excited states in 52Fe have been determined up to spin 10\hbar in the
reaction 28Si + 28Si at 115 MeV by using \gamma-ray spectroscopy methods at the
GASP array. The excitation energy of the yrast 10+ state has been determined to
be 7.381 MeV, almost 0.5 MeV above the well known \beta+-decaying yrast 12+
state, definitely confirming the nature of its isomeric character. The mean
lifetimes of the states have been measured by using the Doppler Shift
Attenuation method. The experimental data are compared with spherical shell
model calculations in the full pf-shell.Comment: 9 pages, RevTeX, 7 figures include
A finite number of regular rotational bands in the superdeformed well of 143Eu
The number of excited superdeformed bands in 143Eu is measured by use of the Fluctuation Analysis Method. Between 10 and 40 rotational bands, displaying typical rotational energy correlations over two consecutive transitions, are populated within a rather narrow range in transition energy, Eγ ≈ 1300-1500 keV. These numbers are close to the values found for normally deformed nuclei and agree with microscopic cranking + band mixing calculations for the specific superdeformed nucleus, which predict the onset of rotational damping to occur at the excitation energy U0 = 1.3-1.6 MeV above the yrast line
Coping with stress: a pilot study of a self-help stress management intervention for patients with epileptic or psychogenic non-epileptic seizures
Purpose: Many patients with epilepsy or psychogenic non-epileptic seizures (PNES) experience high levels of stress. Although psychological interventions have been developed for seizure disorders, few patients can currently access them. We aimed to assess the acceptability and feasibility of a self-help intervention targeting stress in patients with seizures, and to provide preliminary evidence for its effectiveness.
Method: Patients were recruited from outpatient neurology clinics and randomised to an immediate intervention group (n=39), who received the intervention at baseline, or a delayed intervention group (n=43), who received the intervention one month post-baseline. Participants completed self-report questionnaires measuring stress (SSSI), anxiety (GAD-7), depression (NDDI-E), quality of life (EQ-5D), seizure severity and frequency (LSSS-3) at baseline, and at one- and two-month follow-up. Participants also provided telephone feedback. The intervention consisted of a self-help stress management workbook based on an integrative stress model framework.
Results: Although the rate of participants failing to return follow-up information at two months was approximately 50%, those who completed the trial found the intervention acceptable; with the majority rating it as helpful (63.6%) and that they would recommend it to others with seizures (88.1%). A significant reduction in self-reported stress (p = 0.01) with a medium effect size (dz = 0.51) was observed one-month post-intervention. There were no significant changes in any other measures.
Conclusion: The intervention was perceived to be acceptable, safe and helpful by participants. It could be a useful complementary treatment option for reducing stress experienced by patients living with seizure disorders. Further evaluation in a larger trial is warranted
Structure in the E2 quasicontinuum spectrum of Dy154
The evolution of the quasicontinuum spectrum with neutron number has been investigated in the sequence of isotopes Dy152,154,156. The three nuclei display a pronounced collective E2 component. In Dy154 this component shows a splitting into two distinct parts, signifying a structural change along the cascade above the yrast line. The E2 and statistical components are reproduced in simple -cascade calculations; in Dy152 and Dy156 only rotational bands are included, whereas in Dy154 additional vibration-like transitions are required to reproduce the two E2 peaks
Structural changes along and above the yrast line of Dy154
States in Dy154 have been located up to I=48+ and their lifetimes measured. Marked structural changes occur along the yrast line with a transition from prolate to oblate shape, followed by an unexpected return to moderate collectivity at the highest spins. Structural changes with increasing energy above the yrast line are also observed
Evidence for superdeformation in 148Gd
γ-γ transition energy correlation measurements were performed in 148Gd using Compton-suppressed Ge detectors. A broad first ridge was observed for 1.00<Eγ<1.42 MeV. The deduced moment of inertia I(2)=78 h ℏ2MeV- is consistent with superdeformation in 148Gd. The results can be explained by cranked Strutinsky calculations
Level structure of 148Gd up to I=44
The level scheme of 148Gd has been extended to I=44 by use of a Compton-suppressed Ge spectrometer array. Up to I=38 the observed level spectrum consists of spherical and oblate states of aligned-particle type. A change in structure along the yrast line is indicated at higher spins, where fast E2 transitions suggest the onset of collectivity
E0 Transitions and the Depopulation of SD Bands
We present the results of calculations showing that E0 transitions may successfully compete with other types of electromagnetic transitions in the decay out of SD bands
Level structure of
New level schemes of {sup 141}Ba and {sup 139}Xe are proposed from the analyses of spontaneous-fission gamma data from our {sup 252}Cf spontaneous fission Gammasphere runs of 1995 and 2000. By analogy with the N = 85 even-odd isotones {sup 149}Gd, {sup 147}Sm, and {sup 145}Nd, spins and parities were assigned to the observed excited states in {sup 141}Ba and {sup 139}Xe. It appears that spherical shell model neutron excitations plus octupolephonons are an appropriate basis at the lower end of the bands. Going to higher spins it is clear that the soft rotor involving valence protons as well as neutrons becomes increasingly important in the configurations. Level systematics in the N = 85 even-odd isotones from Gd(Z=64) through Te(Z=52), are discussed. The excitation systematics and smooth trends of the analogous levels support the spin and parity assignment for excited levels observed in {sup 141}Ba and {sup 139}Xe. The level systematics and the comparison with neighboring even-even isotopes indicate that quadrupole and octupole collectivity play roles in {sup 141}Ba and {sup 139}$Xe. From Gd(Z=64) through Te(Z=52), increasing excitation energies of the 13/2{sup +} states and lowering relative intensities of the positive parity bands in the N = 85 even-odd isotones may indicate that the octupole strength is becoming weaker for the isotones when approaching the Z = 50 closed shell
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