scholarly journals Gamma Ray Decay Schemes of Levels at Intermediate Energies in 32S

1973 ◽  
Vol 26 (1) ◽  
pp. 17 ◽  
Author(s):  
CE Moss ◽  
RH Spear ◽  
F Ahmad ◽  
AM Baxter ◽  
LE Carlson ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Magnetic Spectrometer ◽  
Excitation Energies ◽  
Intermediate Energies ◽  
Double Focusing

The reaction 32S(p,p'y)32S has been studied with a 12'7 cm by 10�2 cm NaI(TI) y-ray detector in conjunction with a 61 cm double-focusing magnetic spectrometer to determine the y-ray decay schemes of all known levels in 32S between the excitation energies of 5�40 and 7� 15 MeV.

scholarly journals How do we infer shell effects at high-excitation energies? A new spectroscopic probe to search for magic numbers

2019 ◽  
Vol 223 ◽  
pp. 01045 ◽  
Author(s):  
Cebo Ngwetsheni ◽  
José Nicolás Orce
Keyword(s):  
Gamma Ray ◽  
Strength Function ◽  
Dipole Polarizability ◽  
Magic Numbers ◽  
Data Sets ◽  
High Excitation ◽  
Excitation Energies ◽  
Long Range Correlations ◽  
Shell Effects ◽  
Spectroscopic Probe

The nuclear dipole polarizability is mainly governed by the dynamics of the giant dipole resonance and, assuming validity of the brink-Axel hypothesis, has been investigated along with the effects of the low-energy enhancement of the photon strength function for nuclides in medium- and heavy-mass nuclei. Cubic-polynomial fitsto both data sets extrapolated down to a gamma-ray energy of 0.1 MeV show a significantreduction of the nuclear dipole polarizability for semi-magic nuclei, with magic numbers N =28, 50 and 82, which supports shell effects at high-excitation energies in the the quasi-continuum region. This work assigns σ-2 values as sensitive measures of long-range correlations of the nuclear force and provides a new spectroscopic probe to search for “old” and “new” magic numbers at high-excitation energies.

scholarly journals On the quenching of Gamow–Teller strength

1987 ◽  
Vol 65 (6) ◽  
pp. 574-577 ◽  
Author(s):  
J. Rapaport
Keyword(s):  
Cross Sections ◽  
Wave Functions ◽  
Light Nuclei ◽  
Final States ◽  
Excitation Energies ◽  
Intermediate Energies ◽  
Quenching Factor ◽  
Configuration Mixing ◽  
Gamow Teller ◽  
Model Strength

The (p, n) reaction at intermediate energies has been used to measure differential cross sections in light nuclei to final states characterized with a ΔJπ = 1+ transfer (Gamow–Teller (GT) states). Experimental ft values for allowed beta-decay transitions in these nuclei are used to normalize the strength of the GT transitions in units of B(GT). This experimental GT strength is compared with predicted shell–model strength. For p-shell nuclei, the calculated excitation energies of the GT strength using Cohen and Kurath wave functions are in general agreement with the empirical GT distribution. Up to an excitation energy of about 20 MeV, the total experimental and calculated GT strengths are used to obtain the quenching factor, QF = Σ B(GT)exp/Σ B(GT)theor. It is found that QF decreases as the shell gets filled-up. The lowest value seems to occur for single-hole nuclei. This decrease may be explained by configuration mixing not specifically included in the calculations.

Astrophysics and Particle Physics in Space with the Alpha Magnetic Spectrometer

2003 ◽  
Vol 18 (28) ◽  
pp. 1951-1966 ◽  
Author(s):  
Giovanni Lamanna
Keyword(s):  
Particle Physics ◽  
Gamma Ray ◽  
Space Shuttle ◽  
Space Station ◽  
Cosmic Ray ◽  
High Energy ◽  
Magnetic Spectrometer ◽  
High Energy Particle ◽  
Physics Experiment ◽  
Alpha Magnetic Spectrometer

The Alpha Magnetic Spectrometer (AMS) is a high energy particle physics experiment in space scheduled to be installed on the International Space Station (ISS) by 2006 for a three-year mission. After a precursor flight of a prototype detector on board of the NASA Space Shuttle in June 1998, the construction of the detector in its final configuration is started and it will be completed by 2004. The purpose of this experiment is to provide a high statistics measurement of charged particles and nuclei in rigidity range 0.5 GV to few TV and to explore the high-energy (> 1 GeV ) gamma-ray sky. In this paper we describe the detector layout and present an overview of the main scientific goals both in the domain of astrophysics: cosmic-ray origin, age and propagation and the exploration of the most energetic gamma-ray sources; and in the domain of astroparticle: the anti-matter and the dark matter searches.

Levels in 45Sc from Radiative Proton Capture in 44Ca

1974 ◽  
Vol 52 (2) ◽  
pp. 131-139 ◽  
Author(s):  
R. L. Schulte ◽  
J. D. King ◽  
H. W. Taylor
Keyword(s):  
Decay Scheme ◽  
Bound States ◽  
Gamma Ray ◽  
Angular Distributions ◽  
Distribution Data ◽  
Excitation Energies ◽  
Proton Capture ◽  
Resonant States ◽  
Γ Rays ◽  
Γ Ray

A total of 22 resonances has been observed in the 44Ca(p,γ)45Sc reaction within the incident proton energy range of 600 to 930 keV. Gamma-ray singles spectra and γ-ray angular distribution data were accumulated for resonances at Ep = 856 and 906 keV. Both of these resonant states have been found to have spin 3/2. The measured angular distributions of primary γ rays from the resonant states have given spin information on the intermediate bound states of 45Sc with excitation energies above 2 MeV. A γ-ray decay scheme has been derived from the γ-ray spectra. The data indicate new levels at 2151.0, 3525.2, 3548.5, 3584.0, and 3714.3 keV.

Study of levels in 24Mg

1968 ◽  
Vol 46 (12) ◽  
pp. 1381-1401 ◽  
Author(s):  
R. W. Ollerhead ◽  
J. A. Kuehner ◽  
R. J. A. Levesque ◽  
E. W. Blackmore
Keyword(s):  
Angular Correlation ◽  
Beta Decay ◽  
Rotational Band ◽  
Ground State ◽  
Present Experiment ◽  
Gamma Ray ◽  
Axially Symmetric ◽  
Excitation Energies ◽  
Rotational Model ◽  
Rotational Bands

Nineteen levels in 24Mg have been studied utilizing the reaction 12C(16O, αγ)24Mg. Angular correlation measurements have established the spins and parities of levels at excitation energies of 7.35, 7.56, 7.62, 8.44, 8.65, 9.00, 9.15, and 10.1 MeV as 2+, 1−, 3−, 1−, 2+, 2+, 1−, and 0+ respectively. Levels at 8.12 and 13.18 MeV have been identified as the 6+ and 8+ members of the K = 0 ground-state rotational band; levels at 7.81 and 9.52 MeV have been identified as the 5+ and 6+ members of the K = 2 rotational band based on the 2+ level at 4.23 MeV. The existence of doublets has been established at excitation energies of 8.44 and 9.52 MeV; in each case, one member of the doublet is populated in the beta decay of 24Al, and the present experiment indicates that these two levels have spin and parity 4+. Assignments are also suggested for levels at 7.75 MeV (1+) and 8.36 MeV (2+). Gamma-ray spectra have been obtained for levels at 8.86, 9.28, and 9.46 MeV. The properties of levels assigned to rotational bands are compared to the predictions of the rotational model for an axially symmetric nucleus.

Single proton states in odd holmium isotopes

1977 ◽  
Vol 55 (19) ◽  
pp. 1657-1686 ◽  
Author(s):  
J. D. Panar ◽  
O. Straume ◽  
D. G. Burke
Keyword(s):  
Nuclear Structure ◽  
Cross Sections ◽  
Gamma Ray ◽  
Reaction Products ◽  
Excitation Energies ◽  
Light Reaction ◽  
Structure Information ◽  
Structure Factors ◽  
Nilsson Model ◽  
Photographic Emulsions

The (3He,d) and (α,t) reactions have been used to study odd proton states in 157,159,161,163Ho. The beams were provided by tandem Van de Graaff accelerators and the light reaction products were analyzed with magnetic spectrographs and detected with photographic emulsions. Spectra were studied up to excitation energies of ~1.5 MeV for each nuclide with resolutions (FWHM) of ~14 keV for the (3He,d) reaction and ~12 keV for the (α,t) reaction. Information on the l-values was obtained from the ratios of (3He,d) and (α,t) cross sections and from (3He,d) angular distributions. The results are interpreted in terms of the Nilsson model with pairing and Coriolis mixing included. Nuclear structure factors were extracted from the experimental data with the aid of DWBA calculations. Nilsson assignments from previous gamma-ray studies have been confirmed for many low-lying rotational bands. In addition, many new assignments have been made, particularly in the lighter isotopes for which very little nuclear structure information existed previously. A relatively strong l = 0 transition is found in each nuclide and arguments are made to suggest these Iπ = 1/2+ states are gamma vibrations based on the 5/2+[402] states. Similarly, strong l = 2 transitions populate states which may be Iπ = 3/2+ gamma vibrations based on the 7/2+[404] orbitals. Some interesting systematics of the behaviour of single particle states in this region are presented and some anomalies in the populations of the 1/2+[411] and 3/2+[411] states are pointed out.

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