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arXiv · 2512.07023

Lineshape response of plastic scintillator to pair production of 4.44 MeV gamma's

Melisa Ozen·John A. Behr·Michelle Khoo·Felix Klose·Alexandre Gorelov·Dan Melconian
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Abstract

We measure the distribution of energy deposited in a 40x88 mm plastic scintillator by e+ e- pair production of 4.44 MeV gamma-rays. We observe the double-escape peak of 3.42 MeV from pair production by tagging 511 keV annihilation radiation in two high-Z scintillators. The source is a standard commercial neutron source using alpha-emitting 241Am encapsulated with 9Be, which has a reaction branch feeding the first Ipi=2+ state of 12C making the 4.44 MeV gamma-rays. We demonstrate the extraction of the double-escape peak from the large neutron-produced backgound, and explore some of the features and difficulties of this technique with our apparatus.

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Melisa Ozen, John A. Behr, Michelle Khoo, Felix Klose, Alexandre Gorelov, Dan Melconian. 2025-12-07. Lineshape response of plastic scintillator to pair production of 4.44 MeV gamma's. https://doi.org/10.1016/j.nima.2023.168490

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