The total kinetic energy release and fission mass distributions for the fast neutron (En = 3–100 MeV) induced fission of 232Th, 233U, 235U, 237Np, 239Pu, 240Pu, and 242Pu have been measured using the LANSCE facility. The neutron energies were deduced from time-of- flight measurements. The fission fragments were detected using...
Combining geometric mechanics theory, laboratory robotic experiment, and numerical simulation, we study the locomotion in granular media of the simplest noninertial swimmer, the Purcell three-link swimmer. Using granular resistive force laws as inputs, the theory relates translation and rotation of the body to shape changes (movements of the links). This...
The collective chemosensing of nonexcitable mammalian cells involves a biochemical network that features gap junction communications and heterogeneous single cell activities. To understand the integrated multicellular chemosensing, we study the calcium dynamics of micropatterned fibroblast cell colonies in response to adenosine triphosphate (ATP) stimulation. We find that the cross-correlation function...
We demonstrate optomechanical quantum control of the internal electronic states of a diamond nitrogenvacancy (NV) center in the resolved-sideband regime by coupling the NV to both optical fields and surface acoustic waves via a phonon-assisted optical transition and by taking advantage of the strong excited-state electron-phonon coupling of a NV...
Cross sections for radiative capture of neutrons have been measured by the activation technique for stable isotopes of Ba with mass numbers 130, 132, 134, 136, and 138. From separate irradiations using thermal and epithermal neutrons, independent values for the thermal cross sections and effective resonance integrals have been determined....
Forty-six decay chains, assigned to the decay of ²⁸⁸115, were produced using the ²⁴³Am(⁴⁸Ca,3n) ²⁸⁸115 reaction at the Lawrence Berkeley National Laboratory 88-in. cyclotron. The resulting series of α decays were studied using α-photon and α-x-ray spectroscopies. Multiple α-photon coincidences were observed in the element 115 decay chain members, particularly...
Full Text:
Review C, 92(2), 021301.
doi:10.1103/PhysRevC.92.021301
10.1103/PhysRevC.92.021301
American Physical
I led a collaborative project involving a search for an evidence of a gravitational wave background (GWB) with all the spatial correlations allowed by general metric theories of gravity using NANOGrav’s 12.5 year data set. The search found no substantial evidence in favor of the existence of such correlations.
The...
Background: There is a long-term interest in running the fission reaction backward, i.e., studying the "inverse fission" of uranium. The recent availability of beams of n-rich fission fragments has stimulated interest in this endeavor.
Purpose: To search for inverse fission in the reactions Sn-¹²⁴,Sn-¹3² + Mo-¹⁰⁰.
Method: In the Sn-¹²⁴...
Abstract: Background: The cross section for forming a heavy evaporation residue in fusion reactions depends on the capture cross section, the fusion probability, P[subscript CN], i.e., the probability that the projectile-target system will evolve inside the fission saddle point to form a completely fused system rather than reseparating (quasifission), and...