Fri·Nov 26, 2021Friday·November 26, 2021

1. 01*

   Mass measurements of ${}^{60-63}$Ga reduce x-ray burst model uncertainties and extend the evaluated $T=1$ isobaric multiplet mass equation

   S. F. Paul🇨🇦 · J. Bergmann🇩🇪 · J. D. Cardona🇨🇦 · K. A. Dietrich🇨🇦 · E. Dunling🇨🇦 · Z. Hockenbery🇨🇦 · C. Hornung🇩🇪 · C. Izzo🇨🇦 · A. Jacobs🇨🇦 · A. Javaji🇨🇦 · B. Kootte🇨🇦 · Y. Lan🇨🇦 and 18 other authors

   We report precision mass measurements of neutron-deficient gallium isotopes approaching the proton drip line. The measurements of ${}^{60-63}$Ga performed with the TITAN multiple-reflection time-of-flight mass spectrometer provide a more than threefold improvement over the current literature mass uncertainty of ${}^{61}$Ga and mark the first direct mass measurement of ${}^{60}$Ga. The improved precision of the ${}^{61}$Ga mass has important implications for the astrophysical rp process, as it constrains essential reaction Q-values near the ${}^{60}$Zn waiting point. Based on calculations with a one-zone model, we demonstrate the impact of the improved mass data on prediction uncertainties of X-ray burst models. The first-time measurement of the ${}^{60}$Ga ground-state mass establishes the proton-bound nature of this nuclide; thus, constraining the location of the proton drip line along this isotopic chain. Including the measured mass of ${}^{60}$Ga further enables us to extend the evaluated $T=1$ isobaric multiplet mass equation up to $A=60$.

   nucl-exastro-ph.HEPRC(2021)·37 citations
2. 02*

   Properties of correlated fission fragments from neutron induced fission of Np-237 at incident neutron energies between 200 keV and 100 MeV

   D. Connolly (1) · K. B. Montoya (1 and 2) · D. L. Duke (1) · U. Greife (2)🇺🇸 · A. E. Lovell (1)🇺🇸 · S. Mosby (1)🇺🇸 · C. Prokop (1)🇺🇸 · E. Rudziensky (1) · K. Schmitt (1)🇺🇸 · J. Winkelbauer (1) ((1) Los Alamos National Laboratory, Los Alamos, New Mexico, USA, (2) Colorado School of Mines, Golden, Colorado)

   Neutron-induced fission of ${}^{237}$Np has been measured over a wide range of incident neutron energies using a twin Frisch-gridded ionization chamber (TFGIC) and a thin-backed ${}^{237}$Np target. These measurements were performed at the Los Alamos Neutron Science Center - Weapons Neutron Research (LANSCE - WNR) facility, which provides a collimated beam of neutrons with energies ranging from 100s of keV to 100s of MeV. The data were analyzed using the double-energy ($2E$) method, with mass-dependent corrections for prompt-fission neutrons and pulse height defect. Pre- and post-neutron evaporation average total kinetic energy ($⟨TKE⟩$) values are reported for 54 incident neutron energies in the energy range $0.20\le E_n\le 100.0$ MeV and compared to existing data and evaluations. Pre- and post-neutron evaporation mass yields were extracted with a full width at half maximum (FWHM) resolution of 4u and compared to existing data and evaluations. The present $⟨TKE⟩$ and mass yield data agree with previous results and also with statistical models of ${}^{237}$Np$(n,f)$ at incident neutron energies between $E_n=0.2-20.0$ MeV. A flattening of the $⟨TKE⟩$ data is observed (relative to the prediction of the GEF model) above $E_n=20.0$ MeV. However, the interpretation of this discrepancy is unclear as the analysis method's neglect of incomplete momentum transfer at high energies, as well as pre-equilibrium pre-fission phenomena likely have a significant impact on the measurement at such high incident neutron energies.

   nucl-ex0 citations
3. 03*

   Accessing ground state and excited states energies in many-body system after symmetry restoration using quantum computers

   E. A. Ruiz Guzman🇫🇷 · D. Lacroix🇫🇷

   We explore the possibility to perform symmetry restoration with the variation after projection technique on a quantum computer followed by additional post-processing. The final goal is to develop configuration interaction techniques based on many-body trial states pre-optimized on a quantum computer. We show how the projection method used for symmetry restoration can prepare optimized states that could then be employed as initial states for quantum or hybrid quantum-classical algorithms. We use the quantum phase estimation and quantum Krylov approaches for the post-processing. The latter method combined with the quantum variation after projection (Q-VAP) leads to very fast convergence towards the ground-state energy. The possibility to access excited states energies is also discussed. Illustrations of the different techniques are made using the pairing hamiltonian.

   ↳ quant-phcond-mat.supr-connucl-exnucl-thPRC(2022)·53 citations
4. 04*

   Inertial energy dissipation in nuclear dynamics

   Yoritaka Iwata🇯🇵 · Takashi Nishikawa🇯🇵

   We present the TDDFT+Langevin model that incorporates microscopic time-dependent density function theory (TDDFT) with macroscopic Langevin model. By extracting the energy-dependent dissipation effect from the TDDFT dynamics, quantum effects are introduced to the Langevin-type stochastic fission analysis. In this paper, by means of Skyrme nuclear effective interactions, the energy-dependent friction coefficients to be used in Langevin calculations are provided individually for 25 fission nuclei chosen from uranium, plutonium, curium, californium, and fermium isotopes. The validity of the energy-dependent friction coefficients are confirmed by comparing to the existing experimental fission fragment yields. In conclusion, depending on the energy, the transition of energy dissipation mechanism from conventional viscous energy dissipation to inertial energy dissipation is shown.

   ↳ nucl-thnucl-exPRC(2022)·3 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.