Seminars

Monday, Nov 20 at 3:00 PM
1221B Conference Room
Chun Yuen ‘ Tommy’ Tsang,
Tentative Thesis Title: “Constraining the symmetry energy with heavy-ion collisions”
Tuesday, Nov 28 at 11:00 AM
NSCL Lecture Hall 1200
Jutta Escher, Lawrence Livermore National Laboratory
TBA

Abstract:  TBA

Wednesday, Nov 29 at 4:10 PM
NSCL Lecture Hall 1200
Manuel Caamano Fresco, Universidade de Santiago de Compostela
Fission in Inverse Kinematics: A new window to experimental observables

Abstract:  Experimentally, the understanding of the complex, long, and intricate process of nuclear fission is approached by collecting as many observables as possible and from all fissioning systems available. The measured properties of the fissioning system and of the fission products, and their correlations, has led to the current picture where, in a very simplified way, the fission proceeds according certain modes or channels centred around fragments with particular numbers of protons and/or neutrons, which emerge with specific deformations that also drive the sharing of part of the available energy. Most of the information on fission was gathered so far in experiments that use direct kinematics, where the fissioning system can be considered at rest in the laboratory. However, these experiments suffer from two main drawbacks: few observables are measured simultaneously and the fragment atomic number is either absent or poor in resolution. The use of inverse kinematics, where the fissioning system is studied in-flight, opens a possibility to solve those issues and to add new information. In particular, we will discuss the use of magnetic spectrometers in order to provide the simultaneous measurement of the mass and atomic number of the fragments, as well as their velocities, which grants the access to the fissioning system reference frame. The correlation of the measured observables permits to recover properties such as the total kinetic energy or the neutron multiplicity that can be studied and compared with previous measurements. In addition, the measurement of the atomic number allows us to retrieve quantities such as the neutron-to-proton ratio of the fragments, the total excitation energy, and the elongation of the system can be calculated. From there, a few reasonable assumptions are enough to extract the intrinsic and collective excitation energy of the fragments as a function of their atomic number, along with their quadrupole deformation and their distance at scission. The discussion will mainly focus on the study of transfer- and fusion-induced fission of several systems, produced in inverse kinematics at GANIL (France). We will address the latest results on 240Pu and 250Cf, the ongoing analysis of the dependence with the fission energy, as well as future applications to the study of high-energy fission and quasi-fission.

Monday, Dec 04 at 11:00 AM
NSCL Lecture Hall 1200
Steven Ragnar Stroberg, Reed College
TBA

Abstract:  TBA

Tuesday, Dec 05 at 11:00 AM
Biomedical & Physical Sciences Bldg., Rm. 1400
Oleg Korobkin, Los Alamos National Laboratory
TBA

Abstract:  TBA

Wednesday, Dec 06 at 11:00 AM
Biomedical & Physical Sciences Bldg., Rm. 1400
Francesco Raimondi,
TBA

Abstract:  TBA

Thursday, Dec 07 at 10:30 AM
Biomedical & Physical Sciences Bldg., Rm. 1400
Saori Pastore, Los Alamos National Laboratory
TBA

Abstract:  TBA

Friday, Dec 08 at 11:00 AM
NSCL Lecture Hall 1200
Ingo Tews, Institute for Nuclear Theory, University of Washington, Seattle
TBA

Abstract:  TBA

Monday, Dec 11 at 12:30 PM
Biomedical & Physical Sciences Bldg., Rm. 1400
Alan Calder, Stonybrook University
The Quantification of Incertitude in Astrophysical Simulation Codes

Abstract:  We present a study of methodologies for the propagation of epistemic uncertainty, also known as incertitude, in complex astrophysical simulations. We chose the community simulation instrument MESA (Modules for Experiments in Stellar Astrophysics) and simulated the evolution of stars with a ZAMS mass of one solar mass. We explored the case of incertitude in stellar wind parameters, specifically parameters employed to model stellar winds during the red giant and asymptotic giant branch phases of evolution. These parameters are inputs to MESA, and we chose uncertainty intervals for each. Treating MESA as a ``black box,\" we applied two incertitude propagation techniques, Cauchy deviates and quadratic response surface models, to obtain bounds for white dwarf masses at the cessation of thermonuclear burning. These methodologies are applicable to other computational incertitude propagation problems.

Tuesday, Dec 12 at 11:00 AM
NSCL Lecture Hall 1200
Veronica Dexheimer, Kent State University
TBA

Abstract:  TBA