اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدHigh Precision Measurements of Carbon Disulfide Negative Ion Mobility and Diffusion
32
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
High precision measurements were made of reduced mobility, lateral and longitudinal diffusion of CS2- negative ions in 40 Torr CS2 and a 30 - 10 Torr CS2 - CF4 gas mixture. The reduced mobility was found to be 353.0 +/- 0.5 cm^2 Torr / s V in CS2 and 397.4 +/- 0.7 cm^2 Torr / s V in the CS2 - CF4 gas mixture at STP. The lateral diffusion temperatures for these two gases (295 +/- 15 K and 297 +/- 6 K) were found to be in good agreement with room temperature. By contrast longitudinal diffusion temperature was found to be slightly elevated (319 +/- 10 (stat) +/- 8 (sys) K and 310 +/- 20 (stat) +/- 6 (sys) K) though given the errors, room temperature diffusion can not be ruled out. For lateral diffusion significant capture distances (0.21 +/- 0.07 mm and 0.15 +/- 0.03 mm) were measured while for longitudinal diffusion the results were not conclusive.
قيم البحث
اقرأ أيضاً
The correlations of the decay products following the beta decay of nuclei have a long history of providing a low-energy probe of the fundamental symmetries of our universe. Over half a century ago, the correlation of the electrons following the decay
of polarized 60Co demonstrated that parity is not conserved in weak interactions. Today, the same basic idea continues to be applied to search for physics beyond the standard model: make precision measurements of correlation parameters and look for deviations compared to their standard model predictions. Efforts to measure these parameters to the 0.1% level utilizing atom and ion trapping techniques are described.
A negative ion micro time projection chamber (NI$mu$TPC) was developed and its performance studied. An NI$mu$TPC is a novel technology that enables the measurement of absolute $z$ coordinates for self-triggering TPCs. This technology provides full-fi
ducialization analysis, which is not possible with conventional gaseous TPCs, and is useful for directional dark matter searches in terms of background rejection and the improvement of the angular resolution. The developed NI$mu$TPC prototype had a detection volume of 12.8 $times$ 25.6 $times$ 144 mm$^{3}$. The absolute $z$ coordinate was determined with a location accuracy of 16 mm using minority carrieres of SF$_{5}^{-}$. Simultaneously, there was a successful reconstruction of the three-dimensional (3D) tracks with a spatial resolution of 130 $murm{m}$. This is the first demonstration of 3D tracking with the detection of absolute $z$ coordinates, and it is an important step in improving the sensitivity of directional dark matter searches.
The ENUBET facility is a proposed narrow band neutrino beam where lepton production is monitored at single particle level in the instrumented decay tunnel. This facility addresses simultaneously the two most important challenges for the next generati
on of cross section experiments: a superior control of the flux and flavor composition at source and a high level of tunability and precision in the selection of the energy of the outcoming neutrinos. We report here the latest results in the development and test of the instrumentation for the decay tunnel. Special emphasis is given to irradiation tests of the photo-sensors performed at INFN-LNL and CERN in 2017 and to the first application of polysiloxane-based scintillators in high energy physics.
Spherical Proportional Counters (SPCs) are a novel gaseous detector technology employed by the NEWS-G low-mass dark matter search experiment for their high sensitivity to single electrons from ionization. In this paper, we report on the first charact
erization of the single electron response of SPCs with unprecedented precision, using a UV-laser calibration system. The experimental approach and analysis methodology are presented along with various direct applications for the upcoming next phase of the experiment at SNOLAB. These include the continuous monitoring of the detector response and electron drift properties during dark matter search runs, as well as the experimental measurement of the trigger threshold efficiency. We measure a mean ionization energy of $mathrm{W}=27.6pm0.2~mathrm{eV}$ in $mathrm{Ne + CH_4}$ $(2%)$ for 2.8 keV X-rays, and demonstrate the feasibility of performing similar precision measurements at sub-keV energies for future gas mixtures to be used for dark matter searches at SNOLAB.
The general properties needed in targets (sources) for high precision, high accuracy measurements are reviewed. The application of these principles to the problem of developing targets for the Fission TPC is described. Longer term issues, such as the
availability of actinide materials, improved knowledge of energy losses and straggling and the stability of targets during irradiation are also discussed.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
