IBIC2023 - List of Authors (Bai, M.)

Paper	Title	Page
TUP006	Simulation and Shot-by-Shot Monitoring of Linac Beam Halo	191
	A.S. Fisher, M. Bai, T. Frosio, A. Ratti, J. Smedley, J. Wu SLAC, Menlo Park, California, USA I.S. Mostafanezhad, B. Rotter Nalu Scientific, LLC, Honolulu, USA
	FELs require a reproducible distribution of the bunch core at the undulator entrance for robust and reliable lasing. However, various mechanisms drive particles from the core to form a beam halo, which can scrape the beampipe of the undulator and damage its magnets. Collimators can trim the halo, but at the 1-MHz repetition rate of SLAC’s LCLS-II superconducting linac, the collimator jaws can be activated and damaged. The Machine Protection System (MPS) can detect excessive radiation and halt the beam, but repeated MPS trips lead to significant downtime. Halo control begins by studying its structure, formation, and evolution, using a sensitive halo monitor. To that end, we are developing a pixellated diamond sensor. Diamond offers a dynamic range of up to 7 orders of magnitude, extending from the edge of the core to the faint halo expected at greater distances. Nalu Scientific has developed fast electronics for high-rate shot-by-shot readout. Initial tests are starting with a prototype 16-pixel sensor at the beam dump of SLAC’s FACET-II test facility. The tests and simulations will guide more elaborate sensor designs.
	Poster TUP006 [2.602 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-TUP006
About •	Received ※ 07 September 2023 — Revised ※ 08 September 2023 — Accepted ※ 12 September 2023 — Issue date ※ 19 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Simulation and Shot-by-Shot Monitoring of Linac Beam Halo

191

A.S. Fisher, M. Bai, T. Frosio, A. Ratti, J. Smedley, J. Wu
SLAC, Menlo Park, California, USA
I.S. Mostafanezhad, B. Rotter
Nalu Scientific, LLC, Honolulu, USA

FELs require a reproducible distribution of the bunch core at the undulator entrance for robust and reliable lasing. However, various mechanisms drive particles from the core to form a beam halo, which can scrape the beampipe of the undulator and damage its magnets. Collimators can trim the halo, but at the 1-MHz repetition rate of SLAC’s LCLS-II superconducting linac, the collimator jaws can be activated and damaged. The Machine Protection System (MPS) can detect excessive radiation and halt the beam, but repeated MPS trips lead to significant downtime. Halo control begins by studying its structure, formation, and evolution, using a sensitive halo monitor. To that end, we are developing a pixellated diamond sensor. Diamond offers a dynamic range of up to 7 orders of magnitude, extending from the edge of the core to the faint halo expected at greater distances. Nalu Scientific has developed fast electronics for high-rate shot-by-shot readout. Initial tests are starting with a prototype 16-pixel sensor at the beam dump of SLAC’s FACET-II test facility. The tests and simulations will guide more elaborate sensor designs.

Poster TUP006 [2.602 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-TUP006

About •

Received ※ 07 September 2023 — Revised ※ 08 September 2023 — Accepted ※ 12 September 2023 — Issue date ※ 19 September 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)