Cross-facility absolute charge calibration of scintillating screens for laser wakefield accelerated beam diagnostics

Chen-Wei Chiang; Ming-Chang Chou; An-Ping Lee; Yu-Qian Wang; Jhih-Jia Wang; Ming-Wei Lin; Wai-Keung Lau; Shao-Wei Chou

doi:10.1063/5.0225621

Cross-facility absolute charge calibration of scintillating screens for laser wakefield accelerated beam diagnostics

Rev Sci Instrum. 2024 Dec 1;95(12):123306. doi: 10.1063/5.0225621.

Authors

Chen-Wei Chiang^{1

2}, Ming-Chang Chou³, An-Ping Lee³, Yu-Qian Wang¹, Jhih-Jia Wang^{1

2}, Ming-Wei Lin^{1

4}, Wai-Keung Lau³, Shao-Wei Chou^{1

2}

Affiliations

¹ Department of Physics, National Central University, Taoyuan 320317, Taiwan.
² Center for High Energy and High Field Physics, National Central University, Taoyuan 320317, Taiwan.
³ Linac Group, National Synchrotron Radiation Research Center, Hsinchu 300092, Taiwan.
⁴ Institute of Nuclear Engineering and Science, National Tsing Hua University, Hsinchu 300044, Taiwan.

PMID: 39718405
DOI: 10.1063/5.0225621

Abstract

Scintillation screens are widely used to diagnose high-charge density, low-average current electron beams from laser wakefield accelerators (LWFAs). However, the absolute response between emitted photons and electron charge has only been calibrated at a limited number of facilities, and there have been discrepancies between these calibrations. In this report, we comprehensively revised the absolute charge calibration of two high relative brightness scintillating screens of LANEX Regular (Carestream) and PI200 (Mitsubishi) by employing the high-brightness photoinjector at the National Synchrotron Radiation Research Center (NSRRC), which provides electron beams with variable charges (50-350 pC per pulse) and energies (26.55, 34.50, 42.10 MeV). Our results show that the energy-independent fluorescence efficiency of LANEX Regular and PI200 is (7.39 ± 0.38) × 109 and (2.04 ± 0.04) × 1010 photons/sr/pC, respectively, and both screens retained over 98.5% efficiency at accumulated charge densities up to 500 nC/mm2. These results provide a robust framework for applying the scintillation screens in LWFA diagnostics to enhance accuracy and reliability in electron beam characterization.