External beam normalization measurements using atmospheric argon gamma rays

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS

卷:484

Article

Wilkinson, John T.¹  McGuinness, Sean R.¹  Peaslee, Graham F.¹ 

[1] Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA

关键词: PIGE;    External beam;    Beam current integration;    Argon normalization;   

DOI  :  10.1016/j.nimb.2020.10.007

来源: Elsevier

【 摘 要 】

Particle-induced gamma-ray emission spectroscopy is a quantitative, sensitive technique that measures light element abundance in materials using external reference standards with known beam energy and intensity. When the ion beam is used ex vacuo, gamma-ray spectroscopy on targets in air greatly increases sample throughput. However, for most targets the accuracy of these measurements is limited by the uncertainty of the collected charge. An indirect beam current measurement technique has been developed using an ion beam reaction on atmospheric argon, the only atmospheric component with sufficient abundance (similar to 1%) that produces abundant gamma rays with low-energy proton beams. The Ar-40(p,n gamma)K-40 reaction has been studied here, and the characteristic 770 keV gamma ray is observed to serve as a reliable monitor for proton flux. This method allows a real-time calibration of beam intensity on target to measured upstream currents for ion beam analysis at beam energies above 3.5 MeV.

【 授权许可】

Free