Thu·Sep 29, 2022Thursday·September 29, 2022

1. 01*

   Total charge changing cross sections measurements for ${}^{12}$C ion interactions with Al using CR-39 nuclear track detector

   Iftekhar Ahmed

   We are investigating the total charge changing cross-section of 12C by using the CR39 nuclear track detector. Target sandwiched with CR39 of 5 cm x 5 cm area was irradiated with ${}^{12}$C ion at 55 MeV/n and 135 MeV/n at the Wakasa wan Energy Research Center (WERC) and Heavy Ion Medical Accelerator in Chiba (HIMAC), Japan, respectively. Exposed CR39s were etched in ${}^7$N NaOH solution at 70${}^{\circ }$C to visualize the tracks produced by the primary ion beam and its fragmentations. The etching time was chosen between 15 and 25 hours according to exposed densities of ${}^{12}$C ions. The SEIKO FSP 1000 imaging microscope was used to get the image of the front and back surface etch pit simultaneously. Then by counting the projectile track before and after the target, the total charge changing cross-section has been measured. Since there are no previous experimental data to compare, PHITS and Glauber model calculated theoretical values were compared with the previous and this experimental result. From that, the measured data were found in good agreement with the previous and calculated value except for two points at energy 95.7 and 98.6 MeV/n. These two points need more analysis which will be done in the next phase. Measured data in this study will be the first experimental TCC data for ${}^{12}$C+Al interactions in the energy 100 MeV/n. These measured data will be useful to verify the models, optimize shielding in space radiation circumstances, and also to improve treatment planning on therapy, as well.

   nucl-exphysics.med-ph0 citations
2. 02*

   Studying Gamow-Teller transitions and the assignment of isomeric and ground states at $N=50$

   Ali Mollaebrahimi (1,2,3)🇳🇱 · Christine Hornung (2)🇩🇪 · Timo Dickel (2,3)🇩🇪 · Daler Amanbayev (2)🇩🇪 · Gabriella Kripko-Koncz (2)🇩🇪 · Wolfgang R. Plaß(2,3)🇩🇪 · Samuel Ayet San Andrés (2,3)🇩🇪 · Sönke Beck (2,3)🇩🇪 · Andrey Blazhev (4)🇩🇪 · Julian Bergmann (2)🇩🇪 · Hans Geissel (2,3)🇩🇪 · Magdalena Górska (3)🇩🇪 and 41 other authors

   Direct mass measurements of neutron-deficient nuclides around the $N=50$ shell closure below ${}^{100}$Sn were performed at the FRS Ion Catcher (FRS-IC) at GSI, Germany. The nuclei were produced by projectile fragmentation of ${}^{124}$Xe, separated in the fragment separator FRS and delivered to the FRS-IC. The masses of 14 ground states and two isomers were measured with relative mass uncertainties down to $1\times 10^{-7}$ using the multiple-reflection time-of-flight mass spectrometer of the FRS-IC, including the first direct mass measurements of ${}^{98}$Cd and ${}^{97}$Rh. A new $Q_{\mathrm{EC}}=5437\pm 67$ keV was obtained for ${}^{98}$Cd, resulting in a summed Gamow-Teller (GT) strength for the five observed transitions ($0^{+}⟶1^{+}$) as $B(\text{GT})=2.94_{-0.28}^{+0.32}$. Investigation of this result in state-of-the-art shell model approaches sheds light into a better understanding of the GT transitions in even-even isotones at $N=50$. The excitation energy of the long-lived isomeric state in ${}^{94}$Rh was determined for the first time to be $293\pm 21$ keV. This, together with the shell model calculations, allows the level ordering in ${}^{94}$Rh to be understood.

   nucl-exPLB(2023)·12 citations
3. 03*

   Scaling properties of background- and chiral-magnetically-driven charge separation: evidence for detection of the chiral magnetic effect in heavy ion collisions

   Roy A. Lacey (Depts. of Chemistry & Physics, Stony Brook University, NY, USA)🇺🇸

   The scaling properties of the $R_{{\Psi }_2}(\Delta S)$ correlator and the $\Delta \gamma$ correlator are used to investigate a possible chiral-magnetically-driven (CME) charge separation in $p$+Au, $d$+Au, Ru+Ru, Zr+Zr, and Au+Au collisions at ${\sqrt{s}}_{\mathrm{NN}}=200$~GeV, and in $p$+Pb (${\sqrt{s}}_{\mathrm{NN}}=5.02$~TeV) and Pb+Pb collisions at ${\sqrt{s}}_{\mathrm{NN}}=5.02$ and $2.76$~TeV. The results for $p$+Au, $d$+Au, $p$+Pb, and Pb+Pb collisions, show the $1/{\mathrm{N}}_{\mathrm{ch}}$ scaling for background-driven charge separation. However, the results for Au+Au, Ru+Ru, and Zr+Zr collisions show scaling violations which indicate a CME contribution in the presence of a large background. In mid-central collisions, the CME accounts for approximately 27\% of the signal + background in Au+Au and roughly a factor of two smaller for Ru+Ru and Zr+Zr, which show similar magnitudes.

   nucl-exhep-exhep-phnucl-thEPJ Web Conf.(2023)·0 citations
4. 04*

   ${}^{197}$Au($\gamma ,xn;x=1\sim 9$) Reaction Cross Section Measurements using Laser-Driven Ultra-Intense $\gamma$-Ray Source

   D. Wu🇨🇳 · H.Y. Lan🇨🇳 · J.Y. Zhang🇨🇳 · J.X. Liu🇨🇳 · H.G. Lu🇨🇳 · J.F. Lv · X.Z. Wu · H. Zhang🇨🇳 · J. Cai · Q.Y. Ma · Y.H. Xia🇨🇳 · Z.N. Wang and 17 other authors

   We present a new method for the measurements of photonuclear reaction flux-weighted average cross sections and isomeric ratios using a laser-driven bremsstrahlung $\gamma$-ray source. An ultra-bright ultra-fast 60$\sim$250 MeV bremsstrahlung $\gamma$-ray source was established using the 200 TW laser facility in the Compact Laser Plasma Accelerator Laboratory, Peking University, which could cover the energy range from knocking out neutrons to producing pions. Stable quasi-monoenergetic electron beams were generated via laser wakefield acceleration with a charge of 300$\sim$600 pC per shot. The averaged $\gamma$-ray intensities ($⩾$8 MeV) were higher than 10${}^8$ per shot and the instantaneous intensities can reach above 10${}^{19}$ s${}^{-1}$ with a duration time about 6.7 ps. ${}^{65}$Cu($\gamma ,n$)${}^{64}$Cu and ${}^{27}$Al($\gamma ,x$)${}^{24}$Na reactions were used as $\gamma$-ray flux monitors in the experiments. The flux-weighted average cross sections and isomeric ratios of ${}^{197}$Au($\gamma ,xn;x=1\sim 9$) reactions were analyzed through activation measurements. The results showed good agreement with previous works and proved this method to be accurate. The ${}^{197}$Au($\gamma ,xn;x=7\sim 9$) reaction cross sections were first achieved with the highest threshold energy of 71.410 MeV. Theoretical cross sections of TALYS 1.9 were calculated to compare with experiment results. This method offered a unique way of gaining insight into photonuclear reaction research, especially for short-lived isomers which extremely lack experimental data.

   nucl-exphysics.plasm-ph5 citations
5. 05*

   Light-Front Holography Model of the EMC Effect

   Dmitriy N. Kim🇺🇸 · Gerald A. Miller🇺🇸

   A new two-component model of the EMC effect based on Light-Front Holographic QCD (LFHQCD) is presented. The model suggests the EMC effect is the result of the nuclear potential breaking SU(6) symmetry. The model separates the $F_2^A$ nuclear structure function into two parts: a free contribution, involving the addition of proton and neutron structure functions weighted by the number of protons and neutrons respectively, and a nuclear/medium modified contribution that involves a universal function for all nuceli. Further, the model displays a connection with the correlation between the size of the EMC effect and the SRC pair density, $a_2$ - extracted from kinematic plateaus at around $x$ > 1 in inclusive quasi-elastic (QE) scattering.

   ↳ nucl-thhep-phnucl-exPRC(2022)·14 citations
6. 06*

   Studies in Pulse Shape Discrimination for an Optimized ASIC Design

   B. Boxer🇺🇸 · B. Godfrey · C. Grace🇺🇸 · J. Johnson · R. Khandwala · M. Tripathi🇺🇸

   The continued advancements of Silicon Photomultipliers (SiPMs) have made them viable photosensors for low recoil energy Pulse Shape Discrimination (PSD) between fast neutron and gamma interactions when coupled to an appropriate scintillator. At the same time, the large number of channels in a typical array calls for the development of low-cost and low-power electronics. A custom integrated circuit (ASIC) is an ideal solution for this purpose. To assess the requirements for such an ASIC, studies were performed using two scintillators, Stilbene and EJ-276, coupled to a 6 x 6 mm SiPM from Onsemi. We demonstrate that both scintillators are viable for performing PSD for interaction energies from 100 keV to several MeV while optimizing the integration periods used in the PSD metric. These measurements inform the design parameters of the ASIC under development.

   ↳ physics.ins-detnucl-exJINST(2023)·2 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.