Author: Moir, D.C.
Paper Title Page
MOZD4 Uncertainty Quantification of Beam Parameters in a Linear Induction Accelerator Inferred from Bayesian Analysis of Solenoid Scans 34
 
  • M.A. Jaworski, D.C. Moir, S. Szustkowski
    LANL, Los Alamos, New Mexico, USA
  
  Lin­ear in­duc­tion ac­cel­er­a­tors (LIAs) such as the DARHT at Los Alamos Na­tional Lab­o­ra­tory make use of the beam en­ve­lope equa­tion to sim­u­late the beam and de­sign ex­per­i­ments. Ac­cepted prac­tice is to infer beam pa­ra­me­ters using the so­le­noid scan tech­nique with op­ti­cal tran­si­tion ra­di­a­tion (OTR) beam pro­files. These scans are then an­a­lyzed with an en­ve­lope equa­tion solver to find a so­lu­tion con­sis­tent with the data and ma­chine pa­ra­me­ters (beam en­ergy, cur­rent, mag­netic field, and geom­e­try). The most com­mon code for this pur­pose with flash-ra­di­og­ra­phy LIAs is xtr [1]. The code as­sumes the ma­chine pa­ra­me­ters are per­fectly known and that beam pro­files will fol­low a nor­mal dis­tri­b­u­tion about the best fit and solves by min­i­miz­ing a chi-square-like met­ric. We con­struct a Bayesian model of the beam pa­ra­me­ters al­low­ing mach­ing pa­ra­me­ters, such as so­le­noid po­si­tion, to vary within rea­son­able un­cer­tainty bounds. Pos­te­rior dis­tri­b­u­tion func­tions are con­structed using Markov-Chain Monte Carlo (MCMC) meth­ods to eval­u­ate the ac­cu­racy of the xtr so­lu­tion un­cer­tain­ties and the im­pact of fi­nite pre­ci­sion in mea­sure­ments.
[1] P.W. Allison, "Beam dynamics equations for xtr," Los Alamos Technical Report LA-UR-01-6585. November 2001. 		 
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DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOZD4  
About • Received ※ 05 August 2022 — Revised ※ 11 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 20 August 2022
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