PAC2013 - List of Authors (Lindberg, R.R.)

Paper	Title	Page
THPMA05	Energy Deposition in the Sector 37 Scraper of the Advanced Photon Source Storage Ring	1361
	J.C. Dooling, M. Borland, Y.-C. Chae, R.R. Lindberg ANL, Argonne, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, under contract number DE-AC02-06CH11357. The horizontal scraper in the sector 37 straight section of the Advanced Photon Source storage ring serves as both a diagnostic to probe the edge of the beam as well as the physical aperture when the store is lost. Initially, the scraper was meant only to be a diagnostic; high-density, short-radiation-length material used in the device was intended to stop halo, not the full beam. Damage to this device was recently discovered, and as a result, we began an effort to model and improve the scraper. Modeling with elegant provides loss distributions for several scenarios such as muting one or both rf systems in combination with firing injection kickers. The loss distributions are used as input to a MARS model of the scraper. Beam dumps from 100 mA dissipates a total of 2600 J. Most of this energy is not deposited locally; however, depending on the geometry and physical make-up, sufficient power density exists to damage the device on beam-facing surfaces. Testing is currently planned to examine the suitability of different beam-facing materials. Because of non-local energy deposition, we are evaluating the secondary role for this scraper as a spoiler rather than a beam dump.

Paper

Title

Page

Energy Deposition in the Sector 37 Scraper of the Advanced Photon Source Storage Ring

1361

J.C. Dooling, M. Borland, Y.-C. Chae, R.R. Lindberg
ANL, Argonne, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, under contract number DE-AC02-06CH11357.
The horizontal scraper in the sector 37 straight section of the Advanced Photon Source storage ring serves as both a diagnostic to probe the edge of the beam as well as the physical aperture when the store is lost. Initially, the scraper was meant only to be a diagnostic; high-density, short-radiation-length material used in the device was intended to stop halo, not the full beam. Damage to this device was recently discovered, and as a result, we began an effort to model and improve the scraper. Modeling with elegant provides loss distributions for several scenarios such as muting one or both rf systems in combination with firing injection kickers. The loss distributions are used as input to a MARS model of the scraper. Beam dumps from 100 mA dissipates a total of 2600 J. Most of this energy is not deposited locally; however, depending on the geometry and physical make-up, sufficient power density exists to damage the device on beam-facing surfaces. Testing is currently planned to examine the suitability of different beam-facing materials. Because of non-local energy deposition, we are evaluating the secondary role for this scraper as a spoiler rather than a beam dump.