Speaker
Description
Neutron detection technology is undergoing a significant transformation. Gas Electron Multiplier (GEM) based neutron detectors are being considered as suitable candidates to meet the demands of next-generation neutron facilities and experiments as they offer high-rate capability ($\text{MHz/cm}^2$), large-area coverage ($\sim \text{m}^2$), and good spatial resolution ($\sim \text{mm}$). In addition to this, it can also work as substitute for traditionally used $^3\mathrm{He}$ based detectors, which are becoming expensive due to the limited availability of $^3\mathrm{He}$ gas. In this context, we have developed a new position-sensitive GEM detector based on a Boron-10 coated drift cathode for neutron detection.
We report the testing of a triple GEM detector with neutrons from $^{252}\mathrm{Cf}$ source. A 10 cm x 10 cm GEM detector prototype consisting of more than 500 pads, each with 4 mm x 4 mm dimension was built at VECC. The cathode plane of the detector was divided into borated and non-borated regions, each of 3 cm x 3 cm area, respectively. $Ar:CO_2$ in 70:30 gas mixture was used for the experiment. A 10 cm thick High Density Polyethylene (HDPE) block was used as the moderator for the incoming neutrons. The actual experimental layout will be discussed in detail. Pad signals were read via 128 channel with self-triggered CBM-MUCH XYTER electronics coupled to a free streaming DAQ. At certain operating conditions, a clear distinction in the hits from the two regions were observed. A systematic study over a range of voltages was carried out and hits in borated and non-borated region have been compared to understand the impact of the gamma background. The gamma rejection capability of this detector at low gain will be highlighted. In addition to this, extensive Monte Carlo simulations with GEANT4 have been performed after appropriate detector modelling to optimize the $^{10}\mathrm{B}$ thickness. A neutron detection efficiency of 1.7% has been estimated for an applied voltage of 3500 V.
The detector configuration, its response in terms of neutron detection efficiency and cluster size variation with voltage for the two regions will be reported and discussed in detail. By Comparing the 2D response for borated and non-borated regions, the imaging capability of this detector for neutron radiography applications will be highlighted.
| Position | Research scholar |
|---|---|
| Affiliation | VECC Kolkata |
| Country | India |