2011 Particle Accelerator Conference - List of Authors (Hetzel, C.)

Paper	Title	Page
MOP192	NSLS-II BPM System Protection from Rogue Mode Coupling	450
	A. Blednykh, B. Bacha, A. Borrelli, M.J. Ferreira, C. Hetzel, H.-C. Hseuh, B.N. Kosciuk, S. Krinsky, O. Singh, K. Vetter BNL, Upton, Long Island, New York, USA
	Funding: Work supported by DOE contract DE-AC02-98CH10886 Rogue mode RF shielding has been successfully designed and implemented into the production multipole vacuum chambers. In order to avoid systematic errors in the NSLS-II BPM system we introduced frequency shift of HOM's by using RF metal shielding located in the antechamber slot of each multipole vacuum chamber. To satisfy the pumping requirement the face of the shielding has been perforated with roughly 50 percent transparency. It stays clear of synchrotron radiation in each chamber.

TUP227	Status of NSLS-II Storage Ring Vacuum Systems	1244
	H.-C. Hseuh, A. Blednykh, L. Doom, M.J. Ferreira, C. Hetzel, J. Hu, S. Leng, C. Longo, V. Ravindranath, K. Roy, S.K. Sharma, F.J. Willeke, K. Wilson, D. Zigrosser BNL, Upton, Long Island, New York, USA
	Funding: Work performed under the auspices of U.S. Department of Energy, under contract DE-AC02-98CH10886 National Synchrotron Light Source II (NSLS-II), being constructed at Brookhaven National Laboratory, is a 3- GeV, high-flux and high-brightness synchrotron radiation facility with a nominal current of 500 mA. The storage ring vacuum system has extruded aluminium chambers, with ante-chamber for photon fans and distributed NEG strip pumping. Discrete photon absorbers are used to intercept the un-used bending magnet radiation. In-situ bakeout is implemented to achieve fast conditioning during initial commissioning and after interventions.

TUP286	Development and Testing of Carbon Fiber Vacuum Chamber Supports for NSLS-II	1364
	B.N. Kosciuk, C. Hetzel, J.A. Kierstead, V. Ravindranath, S.K. Sharma, O. Singh BNL, Upton, Long Island, New York, USA
	The NSLS-II Synchrotron Light Source, a 3 GeV electron storage ring currently under construction at Brookhaven National Laboratory is expected to provide exceptional orbit stability in order to fully utilize the very small emittance of the electron beam. In order to realize this, the beam position monitor (BPM) pick up electrodes which are part of the orbit feedback system must have a high degree of mechanical and thermal stability. In the baseline design, this would be accomplished by using flexible invar plates to support the multi-pole vacuum chamber at the positions where the BPM pick up electrodes are mounted. However, it was later discovered that the close proximity of the invar supports to the adjacent focusing magnets had an adverse affect on the magnetic fields. To mitigate this issue, we propose the use of carbon fiber composite in place of invar as a low CTE (coefficient of thermal expansion) material. Here we show the design, development and testing of thermally stable composite supports capable of sub-micron thermal stability.

Paper

Title

Page

NSLS-II BPM System Protection from Rogue Mode Coupling

450

A. Blednykh, B. Bacha, A. Borrelli, M.J. Ferreira, C. Hetzel, H.-C. Hseuh, B.N. Kosciuk, S. Krinsky, O. Singh, K. Vetter
BNL, Upton, Long Island, New York, USA

Funding: Work supported by DOE contract DE-AC02-98CH10886
Rogue mode RF shielding has been successfully designed and implemented into the production multipole vacuum chambers. In order to avoid systematic errors in the NSLS-II BPM system we introduced frequency shift of HOM's by using RF metal shielding located in the antechamber slot of each multipole vacuum chamber. To satisfy the pumping requirement the face of the shielding has been perforated with roughly 50 percent transparency. It stays clear of synchrotron radiation in each chamber.

TUP227

Status of NSLS-II Storage Ring Vacuum Systems

1244

H.-C. Hseuh, A. Blednykh, L. Doom, M.J. Ferreira, C. Hetzel, J. Hu, S. Leng, C. Longo, V. Ravindranath, K. Roy, S.K. Sharma, F.J. Willeke, K. Wilson, D. Zigrosser
BNL, Upton, Long Island, New York, USA

Funding: Work performed under the auspices of U.S. Department of Energy, under contract DE-AC02-98CH10886
National Synchrotron Light Source II (NSLS-II), being constructed at Brookhaven National Laboratory, is a 3- GeV, high-flux and high-brightness synchrotron radiation facility with a nominal current of 500 mA. The storage ring vacuum system has extruded aluminium chambers, with ante-chamber for photon fans and distributed NEG strip pumping. Discrete photon absorbers are used to intercept the un-used bending magnet radiation. In-situ bakeout is implemented to achieve fast conditioning during initial commissioning and after interventions.

TUP286

Development and Testing of Carbon Fiber Vacuum Chamber Supports for NSLS-II

1364

B.N. Kosciuk, C. Hetzel, J.A. Kierstead, V. Ravindranath, S.K. Sharma, O. Singh
BNL, Upton, Long Island, New York, USA

The NSLS-II Synchrotron Light Source, a 3 GeV electron storage ring currently under construction at Brookhaven National Laboratory is expected to provide exceptional orbit stability in order to fully utilize the very small emittance of the electron beam. In order to realize this, the beam position monitor (BPM) pick up electrodes which are part of the orbit feedback system must have a high degree of mechanical and thermal stability. In the baseline design, this would be accomplished by using flexible invar plates to support the multi-pole vacuum chamber at the positions where the BPM pick up electrodes are mounted. However, it was later discovered that the close proximity of the invar supports to the adjacent focusing magnets had an adverse affect on the magnetic fields. To mitigate this issue, we propose the use of carbon fiber composite in place of invar as a low CTE (coefficient of thermal expansion) material. Here we show the design, development and testing of thermally stable composite supports capable of sub-micron thermal stability.