PAC2013 - List of Authors (Duggins, D.O.)

Paper	Title	Page
WEPBA09	Changes in Electron Cloud Density with Beam Conditioning at CesrTA	904
	J.P. Sikora, J.A. Crittenden, D.O. Duggins, Y. Li, X. Liu Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: This work is supported by the US National Science Foundation PHY-0734867, PHY-1002467, and the US Department of Energy DE-FC02-08ER41538, DE-SC0006505. We compare measurements of electron cloud (EC) buildup in uncoated and TiN-coated aluminum vacuum chambers as a function of integrated beam dose up to 1140 amp-hours. The EC density in newly installed bare aluminum chambers increases with beam dose, while the EC density in the TiN-coated chambers decreases with dose under the same beam conditions. Several techniques are used to monitor EC buildup. These include shielded pickups that measure the flux of cloud electrons onto the beampipe wall, and a TE wave resonance technique that measures the EC density within the volume of the beam-pipe. These measurements were made at the Cornell Electron Storage Ring, which has been reconfigured as a test accelerator CesrTA, providing positron and electron beams with energies ranging from 2 GeV to 5 GeV and a variety of bunch train configurations.

Paper

Title

Page

Changes in Electron Cloud Density with Beam Conditioning at CesrTA

904

J.P. Sikora, J.A. Crittenden, D.O. Duggins, Y. Li, X. Liu
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: This work is supported by the US National Science Foundation PHY-0734867, PHY-1002467, and the US Department of Energy DE-FC02-08ER41538, DE-SC0006505.
We compare measurements of electron cloud (EC) buildup in uncoated and TiN-coated aluminum vacuum chambers as a function of integrated beam dose up to 1140 amp-hours. The EC density in newly installed bare aluminum chambers increases with beam dose, while the EC density in the TiN-coated chambers decreases with dose under the same beam conditions. Several techniques are used to monitor EC buildup. These include shielded pickups that measure the flux of cloud electrons onto the beampipe wall, and a TE wave resonance technique that measures the EC density within the volume of the beam-pipe. These measurements were made at the Cornell Electron Storage Ring, which has been reconfigured as a test accelerator CesrTA, providing positron and electron beams with energies ranging from 2 GeV to 5 GeV and a variety of bunch train configurations.