Bulletin of the American Physical Society
Joint Fall 2011 Meeting of the Texas Sections of the APS, AAPT, and Zone 13 of the SPS
Volume 56, Number 7
Thursday–Saturday, October 6–8, 2011; Commerce, Texas
Session D1: Nuclear Physics I |
Hide Abstracts |
Chair: Robert Tribble, Texas A&M University Room: Sam Rayburn Center Second Floor, Room Innovations A |
Friday, October 7, 2011 1:40PM - 1:52PM |
D1.00001: Simulation of Fast Neutronics in an Accelerator-Driven Sub-Critical Core C. Gwyn Rosaire, Akhdiyor Sattarov, Peter McIntyre, Pavel Tsvetkov Accelerator-driven subcritical fission in a molten salt core (ADSMS) is being developed as a technology for green nuclear power. ADSMS burns its fertile fuel to completion, it cannot melt down, and it destroys long-lived minor actinides. The ADSMS core consists of a vessel filled with a molten salt eutectic of UCl$_{3}$ and NaCl. The fast neutronics of ADSMS makes possible two unique benefits: isobreeding, a steady-state equilibrium in which $^{238}$U is bred to $^{239}$Pu and the $^{239}$Pu fissions, and destruction of minor actinides, in which fission of the intermediary nuclides dominates of breeding. Results of simulations of the fast neutronics in the ADSMS core will be presented. [Preview Abstract] |
Friday, October 7, 2011 1:52PM - 2:04PM |
D1.00002: The Beta Delayed Proton and Gamma Decay of $^{27}$P For Nuclear Astrophysics E. Simmons, L. Trache, A. Banu, M. McCleskey, B. Roeder, A. Spiridon, R.E. Tribble, T. Davinson, P.J. Woods, G.J. Lotay, J. Wallace, D. Doherty, A. Saastamoinen The creation site of $^{26}$Al is still under debate. It is thought to be produced in hydrogen burning and in explosive helium burning in novae and supernovae, and possibly also in the H-burning in outer shells of red giant stars. Also, the reactions for its creation or destruction are not completely known. When $^{26}$Al is created in novae, the reaction chain is: $^{24}$Mg(p,$\gamma )^{25}$Al($\beta $+v)$^{25}$Mg(p,$\gamma )^{26}$Al, but this chain can be by-passed by another chain: $^{25}$Al(p,$\gamma )^{26}$Si(p,$\gamma )^{27}$P and it can also be destroyed directly. The reaction $^{26m}$Al(p,$\gamma )^{27}$Si* is another avenue to bypass the production of $^{26}$Al and it is dominated by resonant capture. We study these resonances by an indirect method, through the $\beta $-decay of $^{27}$P. We use $^{27}$P produced and separated with MARS and a setup which allows increased efficiency for low energy protons and for high-energy gamma-rays. We measure gamma-rays and $\beta $-delayed protons emitted from states above the proton threshold in the daughter nucleus $^{27}$Si (S$_{p}$ = 7.463 MeV) to identify and characterize the resonances. Its lifetime was also measured with accuracy under 1{\%}. [Preview Abstract] |
Friday, October 7, 2011 2:04PM - 2:16PM |
D1.00003: Trojan Horse Method and its application to explosive nucleosynthesis Rosario Gianluca Pizzone, Livius Trache, Claudio Spitaleri, Robert Tribble, Marco La Cognata, Giuseppe Rapisarda, Brian Roeder, Brad Richard, Roberta Sparta' In many astrophysical scenarios a key role is played by radioactive-ion-induced reaction. After recent discoveries on the field of gamma ray astronomy it was realized that many pieces of informations on massive stars nucleosynthesis can be achieved after studying the $^{26}Al$ abundance and the related gamma emission in the Galactic plane. For its understanding a detailed investigation of the nuclear processes producing or destroying this isotope is necessary. Direct measurements of nuclear reaction rates are usually hard to perform since the involved cross sections are very small and especially in the case of radioactive ion beams for which intensities can be significantly lower than stable beams. Thus the role of indirect methods become crucial as they can give information on nuclear reaction cross sections in energy ranges as low as the ones required for astrophysical studies. Among them the Trojan Horse Method gives the possibility to study all particle-induced reactions (both charged or neutrons) in the astrophysical energy ranges under appropriate hypotheses. [Preview Abstract] |
Friday, October 7, 2011 2:16PM - 2:28PM |
D1.00004: The evaluation of a new method to extract spectroscopic factors using asymptotic normalization coefficients and the astrophysical $^{14}$C(n,$\gamma$)$^{15}$C reaction rate M. McCleskey, A.M. Mukhamedzhanov, L. Trache, A. Banu, V. Goldberg, B.T. Roeder, E.N. Simmons, A. Spiridon, R.E. Tribble A new method to determine spectroscopic factors (SFs) that utilizes asymptotic normalization coefficients (ANCs) has been tested at Texas A$\&$M, using $^{15}$C as a test case. The method would use the ANC to fix the external contribution to a non-peripheral reaction which would otherwise be free to vary to unphysical values in a traditional approach. The investigation consisted of two parts. First, the ANC for the $^{14}$C+n configuration in $^{15}$C was determined from the heavy ion neutron transfer reaction $^{13}$C($^{14}$C,$^{15}$C)$^{12}$C and the inverse kinematics reaction d($^{14}$C,p)$^{15}$C. Both of these reactions were measured at sufficiently low energy to be peripheral. Next, a non-peripheral reaction $^{14}$C(d,p)$^{15}$C was measured with an incident deuteron energy of 60 MeV, and this reaction was used along with the previously determined ANC to attempt to find the SF. The ANC was also used to calculate the astrophysical neutron direct capture rate for $^{14}$C(n,$\gamma$)$^{15}$C, which was compared with recent direct experimental results. [Preview Abstract] |
Friday, October 7, 2011 2:28PM - 2:40PM |
D1.00005: New Results with TECSA B.T. Roeder, M. McCleskey, L. Trache, A.A. Alharbi, A. Banu, V.Z. Goldberg, E. Simmons, A. Spiridon, R.E. Tribble, S. Cherubini, M. Gulino, R.G. Pizzone, R. Sparta, C. Spitaleri, T. Davinson, J. Wallace, P.J. Woods The Texas A\&M-Edinburgh-Catania Silicon detector Array (TECSA) is a collaborative effort to build a high-efficiency detector Si array useful for measuring reactions of interest for nuclear astrophysics and nuclear structure. The array consists of up to 16 Micron Semiconductor YY1 detectors that are each 300 $\mu$m thick. Each detector has 16 annular ring sectors to measure the energy and the scattering angle of the detected particles. So far, we have conducted two experiments with TECSA at Cyclotron Institute at Texas A\&M Univ. In the first, we measured the d($^{14}$C,p)$^{15}$C reaction at 11.7 MeV/u. In the second, we measured d($^{26}$Al,p)$^{27}$Al with an $^{26}$Al secondary beam prepared in-flight with MARS. Angular distributions were obtained for both reactions at backward angles. The protons were measured both as singles events and in coincidence with timing signals from the cyclotron RF and a scintillator to measure coincidence between the protons and the beam. Results of the data analysis for the d($^{14}$C,p)$^{15}$C run and preliminary results from the d($^{26}$Al,p)$^{27}$Al run will be presented. Also, prospects for the future use of this detector array will be discussed.\\[0pt] $^{*}$Work supported by US DOE, INFN and STFC (UK). [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700