In this work, a new device developed to measure the transverse diffusion of electrons in gases is described. In this device, electrons are generated in a semitransparent cesium iodide (CsI) ...photocathode, exposed to xenon VUV light from a pulsed Xe lamp. Electrons are allowed to drift a fixed distance, which can be varied between 3.5 and 60 mm, and the charge is collected in a multistrip anode electrode. In the present work, we report the results obtained in xenon and in methane under reduced electric fields of 0.92 and 1.53 Td, for drift distances between 3.5 and 11.5 mm. The electron characteristic energy associated with the transverse diffusion, as measured with this new device, is 5.75 ± 0.45 eV and 7.15 ± 0.63 eV at 0.92 and 1.53 Td, respectively, for xenon and 0.065 ± 0.005 eV and 0.097 ± 0.008 eV at 0.92 and 1.53 Td, respectively, for methane, which are in good agreement with results from the literature.
The knowledge of the electron transverse diffusion in detection media is mandatory to assess the accuracy in systems that require precise event tracking. A new experimental system was developed to ...measure the transverse diffusion of electrons in gases. Electrons are generated in a transmissive CsI photocathode by Xe VUV light from a pulsed Xe lamp, and drift a fixed distance that can be varied from 4 to 60 mm. The charge is then multiplied in a GEM and collected in a multistrip target. The results were obtained for Xe and CH4 at two different E/N values, at 800 Torr, for drift distances between 4 and 12 mm. The characteristic energy associated with the transverse diffusion obtained were (5.75±0.45) eV and (7.15±0.63) eV for Xe, and (0.065±0.005) eV and (0.097±0.008) eV for CH4, respectively for 0.92 and 1.53 Td. All values are in good agreement with results from the literature.
The primary scintillation signal in gaseous detectors can be used to obtain the initial interaction time of a detected event, but existing results in the literature for its yield in gaseous xenon are ...scarce and there is not a good agreement between them. In this work, a standard Gas Proportional Scintillation Counter (GPSC) was used to measure the absolute primary scintillation yield of gaseous xenon at 800 Torr for 5.9 keV X-rays, in order to try to clarify its value. The experimental determination was carried out using the ratio between the primary and secondary scintillation signals. The detection efficiencies of both signals were determined by Monte Carlo simulation results were used to correct the measured ratios. A primary scintillation yield of 73.4 ± 8.8 photons by 5.9 keV X-ray was obtained, from which a wp-value, i.e, the average energy necessary to produce a primary scintillation photon in xenon, of 80 ± 12 eV was obtained.
Also, in the same conditions, the primary scintillation was studied in Xenon-Trimethylamine (TMA – (CH3)3N), mixtures with TMA fraction between 0.1% and 1.0%. The primary scintillation signal was only observable at the lowest TMA fraction in the mixture (0.1%). For higher fractions, the primary scintillation signal was not observable, indicating that these may not be suitable mixtures for experiments that use the primary scintillation signal.
A new experimental system was recently developed to measure the mobility of both positive and negative ions: the Dual-Polarity Ion Drift Chamber (DP-IDC). This system is intended to better understand ...the transport properties of ions in gases relevant for the performance of large volume gaseous detectors like the Negative Ion Time Projection Chambers (NITPCs). In this work, we present a description of the experimental setup and technique used, and the initial studies carried out in Xe–SF6 mixtures, whose interest has attracted attention as a possible alternative in searches for the neutrinoless double-beta decay.
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