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Title: Accurate estimation of the RMS emittance from single current amplifier data

This paper presents the SCUBEEx rms emittance analysis, a self-consistent, unbiased elliptical exclusion method, which combines traditional data-reduction methods with statistical methods to obtain accurate estimates for the rms emittance. Rather than considering individual data, the method tracks the average current density outside a well-selected, variable boundary to separate the measured beam halo from the background. The average outside current density is assumed to be part of a uniform background and not part of the particle beam. Therefore the average outside current is subtracted from the data before evaluating the rms emittance within the boundary. As the boundary area is increased, the average outside current and the inside rms emittance form plateaus when all data containing part of the particle beam are inside the boundary. These plateaus mark the smallest acceptable exclusion boundary and provide unbiased estimates for the average background and the rms emittance. Small, trendless variations within the plateaus allow for determining the uncertainties of the estimates caused by variations of the measured background outside the smallest acceptable exclusion boundary. The robustness of the method is established with complementary variations of the exclusion boundary. This paper presents a detailed comparison between traditional data reduction methods and SCUBEEx bymore » analyzing two complementary sets of emittance data obtained with a Lawrence Berkeley National Laboratory and an ISIS H{sup -} ion source.« less
Authors:
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Publication Date:
OSTI Identifier:
813578
Report Number(s):
LBNL--52462
R&D Project: 821401; TRN: US0303938
DOE Contract Number:
AC03-76SF00098
Resource Type:
Conference
Resource Relation:
Conference: Workshop on Negative Ion Sources, CEA Saclay, Gif-sur-Yvette (FR), 05/30/2002--05/31/2002; Other Information: PBD: 31 May 2002
Research Org:
Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
Sponsoring Org:
USDOE Director, Office of Science (US)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; AMPLIFIERS; ANIONS; CURRENT DENSITY; ION SOURCES; PARTICLE BEAMS