A numerical approach to designing a versatile pepper-pot mask for emittance measurement

Abstract

The pepper-pot method is a popular emittance measurement technique for high intensity beams at low energy such as those generated by photo-injectors. In this paper, the beam dynamics in the space charge dominated regime and analytical design criteria for a mask-based emittance measurement (pepper-pot method) are revisited. A tracking code developed to test the performance of a pepper-pot setup is introduced. Examples of such testing are presented with particle distributions that were generated using PARMELA under different focusing conditions. These distributions were numerically tested against a series of mask geometries suggested by analytical criteria. The resulting fine-tuned geometries and beam dynamics features observed are presented.

Design and Experimental Validation of High-Resolution Single-Shot Emittance Diagnostics for Heavy-Ion Beams

“…(1) a pre-verification procedure that is accomplished with an artificial image generated by a particle tracking simulation [26] based on the Monte-Carlo (MC) method and (2) an advanced background removal method (cluster-removal filter) for effectively suppressing speckle and stray noises. This technique enables precise subtraction of the background noise as well as the investigation of the characteristics of different filters.…”