First Measurements of Spin-Dependent Double-Differential Cross Sections and the Gerasimov-Drell-Hearn Integrand from (3)(H)over-right-arrowe((gamma)over-right-arrow, n)pp at Incident Photon Energies of 12.8 and 14.7 MeV

The first measurement of the three-body photodisintegration of longitudinally polarized He-3 with a circularly polarized gamma-ray beam was carried out at the High Intensity gamma-ray Source facility located at Triangle Universities Nuclear Laboratory. The spin-dependent double-differential cross sections and the contributions from the three-body photodisintegration to the He-3 Gerasimov-Drell-Hearn integrand are presented and compared with state-of-the-art three-body calculations at the incident photon energies of 12.8 and 14.7 MeV. The data reveal the importance of including the Coulomb interaction between protons in three-body calculations

A Thermomechanical Leak Valve for Ion Source

Our study aims to design and manufacture a robust, low-cost, reliable leak valve and, study the working characteristics to deliver a stable flow of gas. As a result, a simple thermomechanical leak valve has been developed at the Particle Accelerator Laboratory, Department of Physics, Mizoram University. The leak valve uses a mechanically actuated, stainless steel ball that provides seals against a polished stainless steel seat. Our study shows that the methodology employed in previous studies results in a varying leak rate over time, which is undesirable. Therefore, a new method is introduced for controlling the leak valve. The new methodology helps us maintain a stable leak rate/gas flow as long as we maintain the operating parameters. The amount/leak rate of molecular gas required to produce an efficient yet stable high ion beam current has also been optimized

Search for Spin-Dependent Short-Range Force Using Optically Polarized 3^3He Gas

We propose a new method to detect short-range \textit{P-} and \textit{T-} violating interactions between nucleons, based on measuring the precession frequency shift of polarized $^3$He nuclei in the presence of an unpolarized mass. To maximize the sensitivity, a high-pressure $^3$He cell with thin glass windows (250 $\rm\mu m$) is used to minimize the distance between the mass and $^3$He. The magnetic field fluctuation is suppressed by using the $^3$He gas in a different region of the cell as a magnetometer. Systematic uncertainties from the magnetic properties of the mass are suppressed by flipping both the magnetic field and spin directions. Without any magnetic shielding, our result has already reached the sensitivity of the current best limit. With improvement in uniformity and stability of the field, we can further improve the sensitivity by two orders of magnitude over the force range from $10^{-4}-10^{-2}$ m

First Measurements of Spin-Dependent Double-Differential Cross Sections and the GDH Integrand from \vec{^3He}(\vec{\gamma},n)pp at Incident Photon Energies of 12.8 and 14.7 MeV

The first measurement of the three-body photodisintegration of longitudinally-polarized ^3He with a circularly-polarized \gamma-ray beam was carried out at the High Intensity \gamma-ray Source (HI\gamma S) facility located at Triangle Universities Nuclear Laboratory (TUNL). The spin-dependent double-differential cross sections and the contributions from the three-body photodisintegration to the ^3He GDH integrand are presented and compared with state-of-the-art three-body calculations at the incident photon energies of 12.8 and 14.7 MeV. The data reveal the importance of including the Coulomb interaction between protons in three-body calculations.Comment: 5 pages, 3 figures, accepted in Physical Review Letter

Spin-dependent cross sections from the three-body photodisintegration of He 3 at incident energies of 12.8 and 14.7 MeV

The first measurement of the three-body photodisintegration of polarized 3He using a circularly polarized photon beam has been performed at incident energies of 12.8 and 14.7 MeV. This measurement was carried out at the high-intensity γ-ray source located at Triangle Universities Nuclear Laboratory. A high-pressure 3He target, polarized via spin exchange optical pumping with alkali metals, was used in the experiment. The spin-dependent double- and single-differential cross sections from 3He(γ,n)pp for laboratory angles varying from 30° to 165° are presented and compared with state-of-the-art three-body calculations. The data reveal the importance of including the Coulomb interaction between protons in the three-body calculations

Towards a More Complete and Accurate Experimental Nuclear Reaction Data Library (EXFOR): International Collaboration Between Nuclear Reaction Data Centres (NRDC)

The International Network of Nuclear Reaction Data Centres (NRDC) coordinated by the IAEA Nuclear Data Section (NDS) is successfully collaborating in the maintenance and development of the EXFOR library. As the scope of published data expands (e.g., to higher energy, to heavier projectile) to meet the needs from the frontier of sciences and applications, it becomes nowadays a hard and challenging task to maintain both completeness and accuracy of the whole EXFOR library. The paper describes evolution of the library with highlights on recent developments.Comment: 4 pages, 2 figure

Evaluation of neutron capture cross sections on 60Fe

627-629The production of 60Fe in the slow neutron capture process (s-process) has been discussed in this paper and the reaction cross sections have been evaluated using different nuclear reactions models and tabulated. The energy of proton energy of neutron energy spectrum code (EPEN) has been used to calculate the neutron energy spectrum and tabulated. Model code dependence of the prediction has also been discussed

A tool for calculation of 7Li(p,n)7Be neutron source spectra below the three-body break-up reaction threshold

We developed a new deterministic neutron source spectrum code EPEN - Energy of Proton Energy of Neutron - for a given lithium target thickness, sample angular coverage and proton energy from the reaction threshold to the three-body break-up threshold. The angular differential cross sections of the 7Li(p,n0)7Be and 7Li(p,n1)7Be reactions evaluated by Liskien and Paulsen were adopted above 1.95 MeV while the functional form suggested by Macklin and Gibbons was adopted for the 7Li(p,n0)7Be reaction cross section near threshold. The spectra obtained by EPEN are validated by the experimental spectra and also compared with the spectra predicted by two Monte Carlo codes, SimLiT and PINO. The results of comparison are discussed in detail

A tool for calculation of

We developed a new deterministic neutron source spectrum code EPEN - Energy of Proton Energy of Neutron - for a given lithium target thickness, sample angular coverage and proton energy from the reaction threshold to the three-body break-up threshold. The angular differential cross sections of the 7Li(p,n0)7Be and 7Li(p,n1)7Be reactions evaluated by Liskien and Paulsen were adopted above 1.95 MeV while the functional form suggested by Macklin and Gibbons was adopted for the 7Li(p,n0)7Be reaction cross section near threshold. The spectra obtained by EPEN are validated by the experimental spectra and also compared with the spectra predicted by two Monte Carlo codes, SimLiT and PINO. The results of comparison are discussed in detail