Synthesizing a four-dimensional beam particle distribution frommultiple two-dimensional views
The transverse dynamics of a nearly-monoenergetic particle beam are described by the evolution of the 4D distribution f(x,y,x',y'), where x and y are the transverse spatial coordinates and x' {triple_bond} p{sub x}/p{sub z} and y' {triple_bond} p{sub y}/p{sub z} are the corresponding momentum components divided by the longitudinal momentum component. In present-day experimental practice, such beams are often diagnosed by passing them through an axially-separated pair of slits parallel to the y axis. This selects for x and x' and integrates over y and y'. A sequence of pulses (with the slits at various x positions) yields a 2D projection of the beam phase space, f(x,x'). Another scanner might yield f(y,y') or, using crossed slits, f(x,y). The challenge is that a small set of such 2D scans does not uniquely specify f(x,y,x',y'); correlations in planes other than those measured are unknown. We have developed Monte-Carlo methods and formulated physically-motivated constraints to synthesize a ''reasonable'' set of particles having 2D projectional densities consistent with the experimental data. Such a set may be used to initialize simulations of the downstream beam. The methods and their performance on model problems are described.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE, Lawrence Livermore National Laboratory
- DOE Contract Number:
- DE-AC02-05CH11231
- OSTI ID:
- 881378
- Report Number(s):
- LBNL-49647; HIFAN 1177; R&D Project: Z46010; BnR: AT5015031; TRN: US200612%%818
- Country of Publication:
- United States
- Language:
- English
Similar Records
Use of Projectional Phase Space Data to Infer a 4D Particle Distribution
Reconstruction of a 4D Particle Distribution Using UnderdeterminedPhase-Space Data