| Records |
| Author |
n_TOF Collaboration (Fraval, K. et al); Domingo-Pardo, C.; Giubrone, G.; Tain, J.L. |
| Title |
Measurement and analysis of the Am-241(n,gamma) cross section with liquid scintillator detectors using time-of-flight spectroscopy at the n_TOF facility at CERN |
Type |
Journal Article |
| Year |
2014 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
| Volume |
89 |
Issue |
4 |
Pages |
044609 - 14pp |
| Keywords |
|
| Abstract |
The Am-241(n,gamma) cross section has been measured at the n_TOF facility at CERN using deuterated benzene liquid scintillators, commonly known as C6D6 detectors, and time-of-flight spectrometry. The results in the resolved resonance range bring new constraints to evaluations below 150 eV, and the energy upper limit was extended from 150 to 320 eV with a total of 172 new resonances not present in current evaluations. The thermal capture cross section was found to be sigma(th) = 678 +/- 68 b, which is in good agreement with evaluations and most previous measurements. The capture cross section in the unresolved resonance region was extracted in the remaining energy range up to 150 keV, and found to be larger than current evaluations and previous measurements. |
Address  |
[Fraval, K.; Gunsing, F.; Belloni, F.; Berthoumieux, E.; Lampoudis, C.] CEA Saclay, Irfu, F-91191 Gif Sur Yvette, France, Email: frank.gunsing@cea.fr |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0556-2813 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000335321400001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1778 |
| Permanent link to this record |
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| Author |
n_TOF Collaboration (Fujii, K. et al); Domingo-Pardo, C.; Tain, J.L. |
| Title |
Neutron physics of the Re/Os clock. III. Resonance analyses and stellar (n, gamma) cross sections of Os-186,Os-187,Os-188 |
Type |
Journal Article |
| Year |
2010 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
| Volume |
82 |
Issue |
1 |
Pages |
015804 - 18pp |
| Keywords |
|
| Abstract |
Neutron resonance analyses have been performed for the capture cross sections of Os-186, Os-187, and Os-188 measured at the n_TOF facility at CERN. Resonance parameters have been extracted up to 5, 3, and 8 keV, respectively, using the SAMMY code for a full R-matrix fit of the capture yields. From these results average resonance parameters were derived by a statistical analysis to provide a comprehensive experimental basis for modeling of the stellar neutron capture rates of these isotopes in terms of the Hauser-Feshbach statistical model. Consistent calculations for the capture and inelastic reaction channels are crucial for the evaluation of stellar enhancement factors to correct the Maxwellian averaged cross sections obtained from experimental data for the effect of thermally populated excited states. These factors have been calculated for the full temperature range of current scenarios of s-process nucleosynthesis using the combined information of the experimental data in the region of resolved resonances and in the continuum. The consequences of this analysis for the s-process component of the Os-187 abundance and the related impact on the evaluation of the time duration of galactic nucleosynthesis via the Re/Os cosmochronometer are discussed. |
| Address |
[Fujii, K.; Abbondanno, U.; Belloni, F.; Milazzo, P. M.; Moreau, C.] Ist Nazl Fis Nucl, I-34149 Trieste, Italy, Email: Kaori.Fujii@ts.infn.it |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0556-2813 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
ISI:000279940200009 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ elepoucu @ |
Serial |
410 |
| Permanent link to this record |
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| Author |
Fujita, H. et al; Algora, A.; Estevez-Aguado, E.; Molina, F.; Rubio, B. |
| Title |
Experimental study of Gamow-Teller transitions via the high-energy-resolution O-18(He-3, t)F-18 reaction: Identification of the low-energy “super” -Gamow-Teller state |
Type |
Journal Article |
| Year |
2019 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
| Volume |
100 |
Issue |
3 |
Pages |
034618 - 13pp |
| Keywords |
|
| Abstract |
Using the high-resolution O-18(He-3, t)F-18 reaction at 0 degrees and at 140 MeV/nucleon, Gamow-Teller (GT) transitions were studied. A high energy resolution of 31 keV was achieved by applying dispersion matching techniques. The main part of the observed GT transition strength is concentrated in the transition to the F-18 ground state (g.s.). The absolute values of the reduced GT transition strengths, B(GT), were derived up to E-x = 12 MeV assuming proportionality between the B(GT) values and the reaction cross sections at 0 degrees. The B(GT) value obtained from the beta decay of F-18 (g.s.) -> O-18 (g.s.) was used to determine the proportionality constant. A total B(GT) of 4.06(5) was found and 76(1)% of the strength is concentrated to the ground state of F-18. The obtained B(GT) values were compared with those from the O-18(p, n) F-18 reaction and the mirror symmetric beta(+) decay of Ne-18 -> F-18. The candidates for 1(+) states with isospin T = 1 were identified by comparison with the O-18(p, p') data. The results of shell-model and quasiparticle-random-phase approximation calculations suggest constructive contributions of various configurations to the F-18 ground state, suggesting that this state is the low-energy super GT state. |
| Address |
[Fujita, H.; Fujita, Y.; Adachi, T.; Hatanaka, K.; Hirota, K.; Ishikawa, D.; Matsubara, H.; Okamura, H.; Ong, H. J.; Susoy, G.; Suzuki, T.; Tamii, A.; Zenihiro, J.] Osaka Univ, Res Ctr Nucl Phys, Ibaraki, Osaka 5670047, Japan, Email: hfujita@rcnp.osaka-u.ac.jp |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
|
| ISSN |
2469-9985 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
|
| Notes |
WOS:000488259800004 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4165 |
| Permanent link to this record |
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| Author |
Fujita, Y. et al; Algora, A.; Estevez-Aguado, E; Molina, F; Rubio, B. |
| Title |
High-resolution study of Gamow-Teller excitations in the Ca-42(He-3,t)Sc-42 reaction and the observation of a “low-energy super-Gamow-Teller state” |
Type |
Journal Article |
| Year |
2015 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
| Volume |
91 |
Issue |
6 |
Pages |
064316 - 15pp |
| Keywords |
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| Abstract |
To study the Gamow-Teller (GT) transitions from the T-z = +1 nucleus Ca-42 to the T-z = 0 nucleus Sc-42, where T-z is the z component of isospin T, we performed a (p, n)-type (He-3, t) charge-exchange reaction at 140 MeV/nucleon and scattering angles around 0 degrees. With an energy resolution of 29 keV, states excited by GT transitions (GT states) could be studied accurately. The reduced GT transition strengths B(GT) were derived up to the excitation energy of 13 MeV, assuming the proportionality between the cross sections at 0 degrees and B(GT) values. The main part of the observed GT transition strength is concentrated in the lowest 0.611-MeV, J(pi) = 1(+) GT state. All the other states at higher energies are weakly excited. Shell-model calculations could reproduce the gross feature of the experimental B(GT) distribution, and random-phase-approximation calculations including an attractive isoscalar interaction showed that the 0.611-MeV state has a collective nature. It was found that this state has all of the properties of a “low-energy super-Gamow-Teller state.” It is expected that low-lying J(pi) = 1(+) GT states have T = 0 in the T-z = 0 nucleus Sc-42. However, T = 1 states are situated in a higher energy region. Assuming an isospin-analogous structure in A = 42 isobars, analogous T = 1, 1(+) states are also expected in Ca-42. Comparing the Ca-42(He-3, t)Sc-42 and Ca-42(p, p') spectra measured at 0 degrees, candidates for T = 1 GT states could be found in the 10-12-MeV region of Sc-42. They were all weakly excited. The mass dependence of the GT strength distributions in Sc isotopes is also discussed. |
| Address |
[Fujita, Y.; Fujita, H.; Adachi, T.; Susoy, G.; Hatanaka, K.; Hirota, K.; Ishikawa, D.; Matsubara, H.; Okamura, H.; Ong, H. J.; Suzuki, T.; Tamii, A.; Zenihiro, J.] Osaka Univ, Res Ctr Nucl Phys, Ibaraki, Osaka 5670047, Japan, Email: fujita@rcnp.osaka-u.ac.jp |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0556-2813 |
ISBN |
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Medium |
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| Area |
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Expedition |
|
Conference |
|
| Notes |
WOS:000356928700001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2283 |
| Permanent link to this record |
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| Author |
Fujita, Y. et al; Algora, A.; Estevez-Aguado, E.; Molina, F.; Rubio, B. |
| Title |
High-resolution study of T-z =+2 ->+1 Gamow-Teller transitions in the Ca-44(3He,t)Sc-44 reaction |
Type |
Journal Article |
| Year |
2013 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
| Volume |
88 |
Issue |
1 |
Pages |
014308 - 18pp |
| Keywords |
|
| Abstract |
In order to study the Gamow-Teller (GT) transitions from the T-z = +2 nucleus Ca-44 to the T-z = +1 nucleus Sc-44, where T-z is the z component of isospin T, we performed the (p, n)-type (He-3, t) charge-exchange (CE) reaction at 140 MeV/nucleon and the scattering angles 0 degrees and 2.5 degrees. An energy resolution of 28 keV, that was realized by applying matching techniques to the magnetic spectrometer system, allowed the study of fragmented states. The GT transition strengths, B(GT), were derived up to the excitation energy (E-x) of 13.7 MeV assuming the proportionality between cross sections and B(GT) values. The total sum of B(GT) values in discrete states was 3.7, which was 31% of the sum-rule-limit value of 12. Shell model calculations using the GXPF1J interaction could reproduce the gross features of the experimental B(GT) distribution, but not the fragmentation of the strength. By introducing the concepts of isospin, properties of isospin analogous transitions and states were investigated. (i) Assuming isospin symmetry, the T-z = +2 -> +1 and T-z = -2 -> -1 mirror GT transitions should have the same properties, where the latter can be studied in the beta decay of Cr-44 to V-44. First, we confirmed that the beta-decay half-life T-1/2 of Cr-44 can be reproduced using the B(GT) distribution from the Ca-44(He-3, t) measurement. Then, the 0 degrees, (3He, t) spectrum was modified to deduce the “beta-decay spectrum” and it was compared with the delayed-proton spectrum from the Cr-44 beta decay. The two spectra were mostly in agreement for the GT excitations, but suppression of the proton decay was found for the T = 2 isobaric analog state (IAS). (ii) Starting from the T = 2 ground state of 44Ca, the (3He, t) can excite GT states (state populated by GT transitions) with T = 1, 2, and 3. On the other hand, the Ca-44(p, p') reaction can excite spin-M1 states (states populated by spin-M1 transitions) with T = 2 and 3 that are analogous to the T = 2 and 3 GT states, respectively. By comparing the spectra from these two reactions, a T value of 2 is suggested for several GT states in the E-x = 11.5-13.7 MeV region. (iii) It has been suggested that the T = 2, J(pi) = 0(+) double isobaric analog state (DIAS) at 9.338 MeV in the T-z = 0 nucleus Ti-44 forms an isospin-mixed doublet with a subsidiary 0(+) state at 9.298 MeV. Since no corresponding state was found in the T-z = +1 nucleus Sc-44, we suggest T = 0 for the subsidiary state. |
| Address |
[Fujita, Y.; Fujita, H.] Osaka Univ, Dept Phys, Toyonaka, Osaka 5600043, Japan, Email: fujita@rcnp.osaka-u.ac.jp |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0556-2813 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000321839100001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1495 |
| Permanent link to this record |
