arXiv subjects

Raj Ganesh Pala

Publications and source records attributed to Raj Ganesh Pala.

2 recordsLinked to original sources

arXiv2026

Experimental Determination of Slow-Neutron Detection Efficiency and Background Discrimination in Mixed Radiation Fields Using Differential CR-39 Track Detectors

Measuring slow neutrons is difficult when the radiation field also contains charged particles and fast neutrons, especially when the radiation composition is not known in advance. In this work, we present a tested method to measure slow neutron fluence using CR-39 solid state nuclear track detectors. Two detectors are used together: a boron coated CR-39 detector and an uncoated CR-39 detector.The uncoated detector records tracks from charged particles and fast neutrons but does not respond to slow neutrons. The boron coated detector additionally detects charged particles produced when slow neutrons react with boron and generate lithium and alpha particles. Subtracting the track density of the uncoated detector from that of the boron coated detector provides a reliable and conservative measure of slow neutrons.Experiments using a reference thermal neutron source show that the difference between the two detectors increases linearly with exposure time. Statistical analysis gives a slow neutron equivalent track rate of 5.84 plus or minus 0.18 tracks per minute, clearly different from zero. The slope of this response is used to determine the detection efficiency of the boron coated detector. The uncoated detector measures the background caused by fast neutron leakage from the source. These results show that boron coated CR-39 detectors cannot be used alone for accurate slow neutron measurements. Reliable neutron fluence determination requires the simultaneous use of an uncoated detector. The difference between the two detectors provides a correct estimate of the thermal neutron flux in mixed radiation fields and where conventional neutron detectors cannot be used.

nucl-ex↗

arXiv2026

CR-39 track detector signatures of slow neutron like signals in Heavy-water electrolysis

We report reproducible track-detector signals consistent with slow neutron capture events, recorded in D$_2$O electrolysis involving D-Pd deposited on Pt cathode. Sensitivity to slow neutrons was achieved using boron-coated CR-39 (BCR) detectors, which register charged particle tracks arising from the $^{10}$B$(n,α)^{7}$Li reaction. These detectors were positioned adjacent to identically prepared uncoated CR-39 control detectors (CCR), which are effectively insensitive to slow neutrons and serve to quantify background contributions from charged particles and fast neutrons under the present experimental conditions. A reproducible differential detector signature (BCR $>$ CCR) would thus indicative of slow neutron fluences. Across multiple independent D$_2$O electrolysis experiments in $0.25~\mathrm{T}$ field, the BCR exhibited significantly excess track signals relative to CCRs. Under these conditions, the observed differential response corresponds to an inferred detector-equivalent slow neutron flux of approximately $(6.7 \pm 0.2)~\mathrm{cm^{-2},s^{-1}}$. Removal of the magnetic field resulted in a reduction of the differential signal by a factor of $\sim6$, indicating a strong empirical dependence on the applied field. In contrast, H$_2$O electrolysis performed under otherwise identical conditions produced no measurable differential detector response, establishing the necessity of deuterated electrochemical conditions for the observed effect. The results are reported strictly as detector signatures consistent with slow neutron capture and do not assert any theoretical explanation. Instead, this work establishes a control verified and detector validated experimental protocol for detecting low flux slow neutrons, and provides empirical constraints relevant to slow neutron studies in experiments involving metal-deuteride systems.

physics.ins-det↗