Demonstrating imaging plate detector stacks for proton radiography using exploding pusher capsules

Journal Article · 23 December 2023 · Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment

DOI: https://doi.org/10.1016/j.nima.2023.169027 · OSTI ID:2406521

Tubman, E. R.  ^[1]; Pollock, B. B. ^[2]; Higginson, D. P. ^[2]; Larson, D. ^[2]; Ross, J. S. ^[2]; Selwood, M. P.  ^[2]; Swadling, G. ^[2]; Manuel, M. J.-E. ^[3]; Pokornik, M.  ^[4]; Moczulski, K. ^[5]; Tzeferacos, P.  ^[5]; Park, H. -S. ^[2]

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1. Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Imperial College, London (United Kingdom)
2. Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
3. General Atomics, San Diego, CA (United States)
4. Univ. of San Diego, San Diego, CA (United States)
5. Univ. of Rochester, NY (United States)

A new detector design has been fielded on the Omega-60 laser facility using a D³ He backlighter capsule to radiograph a magnetized experiment. D³ He capsules produce a low flux (~ 10⁸ total yield in 4π) of protons requiring detectors with close-to single-particle sensitivity to be employed. The new detector stack consisted of both imaging plate (IP) and CR-39 to detect 14.7 MeV protons where, historically, only CR-39 has been used. IP is sensitive to significant contributions in signal from both x-rays and protons so additional filtering has to be added to attenuate the x-rays. Here, the signals and features observed from a single shot are detected by both IP and CR-39, giving confirmation that it is protons creating the signatures on the IP. Measurements of PSL/pixel are used to calculate approximate on-shot proton yields and agree with commonly measured yields. A second IP is used at the rear of the stack to measure, and subsequently remove, a background signal. The spatial resolution at the IP is limited, primarily, by a range of proton energies with varying deflections being recorded at the detector, causing potential ‘blurring’ of features. We find for this setup that the blurring effect is less than the smallest identifiable features observed at the detector, and therefore of minimal impact. A large benefit to this new stack design is that IP can be scanned and processed on much faster timescales than CR-39 allowing for prompt shot feedback. Future designs and modifications to the stack design fielded on this experiment could help improve the contrast of the radiograph on IP, as well as detecting protons produced at alternative energies.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: AC52-07NA27344
• OSTI ID: 2406521
• Report Number(s): LLNL--JRNL-864512; 1098159
• Journal Information: Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment, Journal Name: Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment Vol. 1060; ISSN 0168-9002
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English