PAC2013 - List of Authors (Kustom, R.)

Paper	Title	Page
WEPSM06	Beam-Induced Heat Load Predictions and Measurements in the APS Superconducting Undulator	1055
	K.C. Harkay, L.E. Boon, M. Borland, Y.-C. Chae, R.J. Dejus, J.C. Dooling, C.L. Doose, L. Emery, Y. Ivanyushenkov, M.S. Jaski, M. Kasa, S.H. Kim, R. Kustom, V. Sajaev, Y. Shiroyanagi, X. Sun ANL, Argonne, USA L.E. Boon Purdue University, West Lafayette, Indiana, USA
	Funding: Work supported by U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357. The first prototype superconducting undulator (SCU0) was successfully installed and commissioned at the Advanced Photon Source (APS) and is delivering photons for user science. The cryosystem was designed to handle a beam-induced heat load of up to 40 W. Prior to operations, detailed predictions of this heat load were made, including that produced by resistive wall heating by the image current, geometric wakefields, synchrotron radiation, electron cloud, and beam losses. The dominant cw source is the resistive wall heat load. The heat load predictions for standard 100 mA user operation were benchmarked using thermal sensors that measure temperatures at various locations in the SCU0 cryostat and along the electron beam chamber. Thermal analysis using the predicted heat loads from the electron beam, using three independent methods, agrees well with the observed measurements.

WEPSM07	Beam-based Alignment of the First Superconducting Undulator at APS	1058
	K.C. Harkay, L.E. Boon, M. Borland, L. Emery, R. Kustom, V. Sajaev, Y. Shiroyanagi, A. Xiao ANL, Argonne, USA L.E. Boon Purdue University, West Lafayette, Indiana, USA
	Funding: Work supported by U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357. The first prototype superconducting undulator (SCU0) was successfully installed and commissioned at the Advanced Photon Source (APS) and is delivering photons for user science. The magnet cores are mounted on but thermally isolated from the beam vacuum chamber. Protecting the SCU0 from high beam-induced heat loads was an important requirement before operating the SCU0 in the storage ring. Precise alignment of the beam vacuum chamber with respect to both the electron beam orbit as well as the synchrotron radiation generated in the upstream dipole magnet was therefore extremely important. The beam vacuum chamber was instrumented with nine thermal sensors. Using the sensors, the chamber alignment was determined with a 100-micron precision. This precision is more than 10 times higher than in a standard aperture scan. Other advantages of the thermal sensor-based alignment method include isolating the SCU0 alignment from other components in the orbit bump and providing good longitudinal spatial resolution. The chamber temperatures agreed well the predicted heat load and dependence on steering. This novel beam-based alignment method and results will be presented.

Paper

Title

Page

Beam-Induced Heat Load Predictions and Measurements in the APS Superconducting Undulator

1055

K.C. Harkay, L.E. Boon, M. Borland, Y.-C. Chae, R.J. Dejus, J.C. Dooling, C.L. Doose, L. Emery, Y. Ivanyushenkov, M.S. Jaski, M. Kasa, S.H. Kim, R. Kustom, V. Sajaev, Y. Shiroyanagi, X. Sun
ANL, Argonne, USA
L.E. Boon
Purdue University, West Lafayette, Indiana, USA

Funding: Work supported by U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
The first prototype superconducting undulator (SCU0) was successfully installed and commissioned at the Advanced Photon Source (APS) and is delivering photons for user science. The cryosystem was designed to handle a beam-induced heat load of up to 40 W. Prior to operations, detailed predictions of this heat load were made, including that produced by resistive wall heating by the image current, geometric wakefields, synchrotron radiation, electron cloud, and beam losses. The dominant cw source is the resistive wall heat load. The heat load predictions for standard 100 mA user operation were benchmarked using thermal sensors that measure temperatures at various locations in the SCU0 cryostat and along the electron beam chamber. Thermal analysis using the predicted heat loads from the electron beam, using three independent methods, agrees well with the observed measurements.

WEPSM07

Beam-based Alignment of the First Superconducting Undulator at APS

1058

K.C. Harkay, L.E. Boon, M. Borland, L. Emery, R. Kustom, V. Sajaev, Y. Shiroyanagi, A. Xiao
ANL, Argonne, USA
L.E. Boon
Purdue University, West Lafayette, Indiana, USA

Funding: Work supported by U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
The first prototype superconducting undulator (SCU0) was successfully installed and commissioned at the Advanced Photon Source (APS) and is delivering photons for user science. The magnet cores are mounted on but thermally isolated from the beam vacuum chamber. Protecting the SCU0 from high beam-induced heat loads was an important requirement before operating the SCU0 in the storage ring. Precise alignment of the beam vacuum chamber with respect to both the electron beam orbit as well as the synchrotron radiation generated in the upstream dipole magnet was therefore extremely important. The beam vacuum chamber was instrumented with nine thermal sensors. Using the sensors, the chamber alignment was determined with a 100-micron precision. This precision is more than 10 times higher than in a standard aperture scan. Other advantages of the thermal sensor-based alignment method include isolating the SCU0 alignment from other components in the orbit bump and providing good longitudinal spatial resolution. The chamber temperatures agreed well the predicted heat load and dependence on steering. This novel beam-based alignment method and results will be presented.