Response of a Li-glass/multi-anode photomultiplier detector to α-particles from 241Am

Abstract

The response of a position-sensitive Li-glass scintillator detector to α-particles from a collimated 241 Am source scanned across the face of the detector has been measured. Scintillation light was read out by an 8 × 8 pixel multi-anode photomultiplier and the signal amplitude for each pixel has been recorded for every position on a scan. The pixel signal is strongly dependent on position and in general several pixels will register a signal (a hit) above a given threshold.The effect of this threshold on hit multiplicity is studied, with a view to optimize the single-hit efficiency of the detector.

Response of a Li-glass/multi-anode photomultiplier detector to collimated thermal-neutron beams

“…The scan shows that signal leakage to adjacent pixels is ∼7-12% when the neutron beam strikes the center of either pixel. This represents a larger spread of scintillation signal into the adjacent pixel than was the case for previous investigations of relatively central pixels with charged-particle beams [32,33] and may be related to the di usely re ecting white paper placed at the front face of the GS20 sheet. α-particle scan results for (non-edge) P36, P37, P44, and P45 [32] demonstrated summed gain-corrected charge distributions that were at across the pixels and boundary regions.…”

“…LEDs and laser light have been used extensively to study the detailed responses of several di erent MAPMTs [22][23][24][25][26][27][28][29][30][31]. Previously, scans of a ∼1 mm collimated beam of ∼4 MeV α-particles from an 241 Am source [32] and ∼100 µm diameter beams of 2.5 MeV protons and deuterons [33] have been used to study the position-dependent response of a SoNDe detector prototype in regions well-removed from the edges of the detector acceptance. Thermal neutrons have also been used to perform rst tests both on similar detectors [34] and on SoNDe modules [21].…”

Response of a Li-glass/multi-anode photomultiplier detector to focused proton and deuteron beams

“…Across the boundary between the pixels, the lightloss gradient increases to 35%/mm. Based upon the α-particle scan results [31], it was anticipated that the sums of the gain-corrected charge distributions would be at across the pixels and the boundary regions. Instead, the results have a slightly convex distribution centered at the pixel edge.…”

“…Knowledge of the behavior of the adjacent pixels as a function of threshold is important for the TOF mode of operation at ESS. In previous work [31] determining responses to scans of ∼1 mm FWHM beams of α-particles, the hit multiplicity (M = 1, M = 2, etc.) for adjacent pixels as a function of the beam-spot position was measured.…”

“…A thermal-neutron interaction with the 6 Li of the Li-glass results in an α-particle (2.05 MeV) and a triton 2.73 MeV). Scans of a collimated beam of ∼4 MeV α-particles from a 241 Am source have been used to study the position-dependent response of a SoNDe detector prototype [31]. Here, in the absence of tritium beams, beams of 2.5 MeV protons and deuterons have been scanned across the face of a SoNDe module.…”