Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userMeasurement of spin-dependent total cross-section difference $Deltasigma_T$ in neutron-proton scattering at 16 MeV
287
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
A new measurement of $Deltasigma_T$ for polarized neutrons transmitted through a polarized proton target at 16.2 MeV has been made. A polarized neutron beam was obtained from the $^{3}rm{H}(d,vec n)^{4}rm{He}$ reaction; proton polarization over 90% was achieved in a frozen spin target of 20 cm$^3$ volume. The measurement yielded the value $Deltasigma_T=(-126pm21pm14)$ mb. The result of a simple phase shift analysis for the $^3S_1-^3D_1$ mixing parameter $epsilon_1$ is presented and compared with the theoretical potential model predictions.
rate research
Read More
We describe a double-scattering experiment with a novel tagged neutron beam to measure differential cross sections for np back-scattering to better than 2% absolute precision. The measurement focuses on angles and energies where the cross section magnitude and angle-dependence constrain the charged pion-nucleon coupling constant, but existing data show serious discrepancies among themselves and with energy-dependent partial wave analyses (PWA). The present results are in good accord with the PWA, but deviate systematically from other recent measurements.
The differential cross section for proton-proton elastic scattering has been measured at a beam energy of 1.0 GeV and in 200 MeV steps from 1.6 to 2.8 GeV for centre-of-mass angles in the range from 12-16 degrees to 25-30 degrees, depending on the energy. Absolute normalisations of typically 3% were achieved by studying the energy losses of the circulating beam of the COSY storage ring as it passed repeatedly through the windowless hydrogen target of the ANKE magnetic spectrometer. It is shown that the data have a significant impact upon a partial wave analysis. After extrapolating the differential cross sections to the forward direction, the results are broadly compatible with the predictions of forward dispersion relations.
A tagged medium-energy neutron beam has been used in a precise measurement of the absolute differential cross section for np back-scattering. The results resolve significant discrepancies within the np database concerning the angular dependence in this regime. The experiment has determined the absolute normalization with 1.5% uncertainty, suitable to verify constraints of supposedly comparable precision that arise from the rest of the database in partial wave analyses. The analysis procedures, especially those associated with evaluation of systematic errors in the experiment, are described in detail so that systematic uncertainties may be included in a reasonable way in subsequent partial wave analysis fits incorporating the present results.
Kr83m with a short lifetime is an ideal calibration source for liquid xenon or liquid argon detector. The 83mKr isomer can be generated through the decay of Rb83 isotope, and Rb83 is usually produced by proton beams bombarding natural krypton atoms. In this paper, we report a successful production of Rb83/Kr83m with 3.4 MeV proton beam energy and measure the production rate with such low proton energy for the first time. Another production attempt was performed with newly available 20 MeV proton beam in China, the production rate is consistent with our expectation. The produced Kr83m source has been successfully injected into PandaX-II liquid xenon detector and yielded enough statistics for detector calibration.
We report the first measurement of the neutron cross section on argon in the energy range of 100-800 MeV. The measurement was obtained with a 4.3-hour exposure of the Mini-CAPTAIN detector to the WNR/LANSCE beam at LANL. The total cross section is measured from the attenuation coefficient of the neutron flux as it traverses the liquid argon volume. A set of 2,631 candidate interactions is divided in bins of the neutron kinetic energy calculated from time-of-flight measurements. These interactions are reconstructed with custom-made algorithms specifically designed for the data in a time projection chamber the size of the Mini-CAPTAIN detector. The energy averaged cross section is $0.91 pm{} 0.10~mathrm{(stat.)} pm{} 0.09~mathrm{(sys.)}~mathrm{barns}$. A comparison of the measured cross section is made to the GEANT4 and FLUKA event generator packages.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
