2011 Particle Accelerator Conference - List of Authors (Sharma, S.K.)

Paper

Title

Page

Design and Preliminary Test of the 1500 MHz NSLS-II Passive Superconducting RF Cavity

910

J. Rose, W.K. Gash, B.N. Kosciuk, V. Ravindranath, S.K. Sharma, R. Sikora, N.A. Towne
BNL, Upton, Long Island, New York, USA
C.H. Boulware, T.L. Grimm, C. Krizmanich, B. Kuhlman, N. Miller, B. Siegel, M.J. Winowski
Niowave, Inc., Lansing, Michigan, USA

NSLS-II is a new ultra-bright 3 GeV 3rd generation synchrotron radiation light source. The performance goals require operation with a beam current of 500mA and a bunch current of at least 0.5mA. Ion clearing gaps are required to suppress ion effects on the beam. The natural bunch length of 3mm is planned to be lengthened by means of a third harmonic cavity in order to increase the Touschek limited lifetime. Earlier work described the design alternatives and the geometry selected for a copper prototype. We subsequently have iterated the design to lower the R/Q of the cavity and to increase the diameter of the beam pipe ferrite HOM dampers to reduce the wakefield heating. A niobium cavity and full cryomodule including LN2 shield, magnetic shield and insulating vacuum vessel have been fabricated and installed.

TUP271

CESR-type SRF Cavity - Meeting the ASME Pressure Vessel Criteria by Analysis

1328

T. Schultheiss, J. Rathke
AES, Medford, NY, USA
V. Ravindranath, J. Rose, S.K. Sharma
BNL, Upton, Long Island, New York, USA

Funding: This work is supported by BNL under contract #147322
Over a dozen CESR-B Type SRF cryomodules have been implemented in advanced accelerators around the world. The cryomodule incorporates a niobium cavity operating in liquid helium at approximately 1.2 bar and at 4.5 K, and therefore, is subjected to a differential pressure of 1.2 bar to the beam vacuum. Over the past few decades niobium RRR values have increased, as manufacturing processes have improved, resulting in higher purity niobium and improved thermal properties. Along with these increases may come a decrease of yield strength, therefore, prior designs such as CESR-B, must be evaluated at the newer strength levels when using the newer high purity niobium. In addition to this the DOE directive 10CFR851 requires all DOE laboratories to provide a level of safety equivalent to that of the ASME Boiler and Pressure Vessel codes. The goal of this work was to analyze the CESR-B Type cavity and compare the results to ASME pressure vessel criteria and where necessary modify the design to meet the code criteria.

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.

THOBS2

Optimization of Magnet Stability and Alignment for NSLS-II

2082

S.K. Sharma, L. Doom, A.K. Jain, P.N. Joshi, F. Lincoln, V. Ravindranath
BNL, Upton, Long Island, New York, USA

Funding: This work was supported by Department of Energy contract DE-AC02-98CH10886
The high-brightness design of NSLS-II requires uncorrelated vertical RMS motion of the multipole magnets on a girder to be less than 25 nm. Also, the highly nonlinear lattice requires alignment of the multipole magnets to 30 microns. The speaker will describe the stability of the girder-magnets assembly and the factors affecting it, such as ambient ground motion and temperature fluctuations in the storage ring. Technical solutions to achieve the desired stability will be presented as well.

Slides THOBS2 [4.431 MB]

MOP276

Applying Cascaded Parameter Scan to Study Top-off Safety in NSLS-II Storage Ring

627

Y. Li, S.V. Badea, W.R. Casey, G. Ganetis, R. Heese, H.-C. Hseuh, P.K. Job, S. Krinsky, B. Parker, T.V. Shaftan, S.K. Sharma, L. Yang
BNL, Upton, Long Island, New York, USA

Funding: Work supported by U.S. DOE, Contract No. DE-AC02-98CH10886
In this paper we introduce a new algorithm, the cascaded parameter scan method, to efficiently carry out the scan over magnet parameters in the safety analysis for the NSLS-II top-off injection. In top-off safety analysis, one must track particles populating phase space through a beamline containing magnets and apertures and clearly demonstrate that for all possible magnet settings and errors, all particles are lost on scrapers within the properly shielded region. In the usual approach, the number of tracking runs increases exponentially with the number of magnet settings. In the cascaded parameter scan method, the number of tracking runs only increases linearly. This reduction of exponential to linear dependence on the number of setpoints, greatly reduces the required computation time and allows one to more densely populate phase space and to increase the number of setpoints scanned for each magnet. An example of applying this approach to analyze an NSLS-II beamline, the damping wiggler beamline, is also given.

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.

WEP201

Status of NSLS-II Booster

1864

S.M. Gurov, A. Akimov, O. Anchugov, A.M. Batrakov, E.A. Bekhtenev, O.V. Belikov, P.B. Cheblakov, V.P. Cherepanov, A.D. Chernyakin, V.G. Cheskidov, I.N. Churkin, A.N. Dubrovin, A. Erokhin, K. Gorchakov, S.E. Karnaev, G.V. Karpov, V.A. Kiselev, V.V. Kobets, V.V. Kolmogorov, V.M. Konstantinov, A.A. Korepanov, E.A. Kuper, V. Kuzminykh, E.B. Levichev, V.R. Mamkin, A.S. Medvedko, O.I. Meshkov, N. Nefedov, V.V. Neyfeld, I.N. Okunev, M. Petrichenkov, V.V. Petrov, A. Polyansky, D.N. Pureskin, A. Rakhimov, S.I. Ruvinsky, T.V. Rybitskaya, L.M. Schegolev, A.V. Semenov, D.V. Senkov, S.S. Serednyakov, S.V. Shiyankov, D.A. Shvedov, S.V. Sinyatkin, V.V. Smaluk, A.V. Sukhanov, L. Tsukanova, A.V. Utkin, K. Yaminov
BINP SB RAS, Novosibirsk, Russia
J.H. DeLong, R.P. Fliller, G. Ganetis, H.-C. Hseuh, I. Pinayev, T.V. Shaftan, S.K. Sharma, O. Singh, Y. Tian, F.J. Willeke
BNL, Upton, Long Island, New York, USA
P.A.E. Elkiaer
Danfysik A/S, Jyllinge, Denmark

The National Synchrotron Light Source II is a third generation light source under construction at Brookhaven National Laboratory. The project includes a highly optimized 3 GeV electron storage ring, linac pre-injector and full-energy booster-synchrotron. Budker Institute of Nuclear Physics builds booster for NSLS-II. The booster should accelerate the electron beam continuously and reliably from minimal 170 MeV injection energy to maximal energy of 3.15 GeV and average beam current of 20 mA. The booster shall be capable of multi-bunch and single bunch operation. This paper summarizes the status of NSLS-II booster and the main designed parameters.

THP216

Progress with NSLS-II Injection Straight Section Design

2528

T.V. Shaftan, A. Blednykh, W.R. Casey, L.R. Dalesio, R. Faussete, M.J. Ferreira, R.P. Fliller, G. Ganetis, R. Heese, H.-C. Hseuh, P.K. Job, E.D. Johnson, B.N. Kosciuk, S. Kowalski, S.L. Kramer, D. Padrazo, B. Parker, I. Pinayev, S.K. Sharma, O. Singh, C.J. Spataro, G.M. Wang, F.J. Willeke
BNL, Upton, Long Island, New York, USA

Funding: This work is supported by U.S. DOE, Contract No.DE-AC02-98CH10886
NSLS-II injection straight section consists of the pulsed and DC/Slow bumps, septa system, beam trajectory correction and diagnostics systems. In this paper we discuss overall injection straight layout, preliminary element designs, specifications for the pulsed and DC magnets and their power supplies, vacuum devices and chambers and diagnostics devices.

Paper	Title	Page
TUP055	Design and Preliminary Test of the 1500 MHz NSLS-II Passive Superconducting RF Cavity	910
	J. Rose, W.K. Gash, B.N. Kosciuk, V. Ravindranath, S.K. Sharma, R. Sikora, N.A. Towne BNL, Upton, Long Island, New York, USA C.H. Boulware, T.L. Grimm, C. Krizmanich, B. Kuhlman, N. Miller, B. Siegel, M.J. Winowski Niowave, Inc., Lansing, Michigan, USA
	NSLS-II is a new ultra-bright 3 GeV 3rd generation synchrotron radiation light source. The performance goals require operation with a beam current of 500mA and a bunch current of at least 0.5mA. Ion clearing gaps are required to suppress ion effects on the beam. The natural bunch length of 3mm is planned to be lengthened by means of a third harmonic cavity in order to increase the Touschek limited lifetime. Earlier work described the design alternatives and the geometry selected for a copper prototype. We subsequently have iterated the design to lower the R/Q of the cavity and to increase the diameter of the beam pipe ferrite HOM dampers to reduce the wakefield heating. A niobium cavity and full cryomodule including LN2 shield, magnetic shield and insulating vacuum vessel have been fabricated and installed.

TUP271	CESR-type SRF Cavity - Meeting the ASME Pressure Vessel Criteria by Analysis	1328
	T. Schultheiss, J. Rathke AES, Medford, NY, USA V. Ravindranath, J. Rose, S.K. Sharma BNL, Upton, Long Island, New York, USA
	Funding: This work is supported by BNL under contract #147322 Over a dozen CESR-B Type SRF cryomodules have been implemented in advanced accelerators around the world. The cryomodule incorporates a niobium cavity operating in liquid helium at approximately 1.2 bar and at 4.5 K, and therefore, is subjected to a differential pressure of 1.2 bar to the beam vacuum. Over the past few decades niobium RRR values have increased, as manufacturing processes have improved, resulting in higher purity niobium and improved thermal properties. Along with these increases may come a decrease of yield strength, therefore, prior designs such as CESR-B, must be evaluated at the newer strength levels when using the newer high purity niobium. In addition to this the DOE directive 10CFR851 requires all DOE laboratories to provide a level of safety equivalent to that of the ASME Boiler and Pressure Vessel codes. The goal of this work was to analyze the CESR-B Type cavity and compare the results to ASME pressure vessel criteria and where necessary modify the design to meet the code criteria.

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.

THOBS2	Optimization of Magnet Stability and Alignment for NSLS-II	2082
	S.K. Sharma, L. Doom, A.K. Jain, P.N. Joshi, F. Lincoln, V. Ravindranath BNL, Upton, Long Island, New York, USA
	Funding: This work was supported by Department of Energy contract DE-AC02-98CH10886 The high-brightness design of NSLS-II requires uncorrelated vertical RMS motion of the multipole magnets on a girder to be less than 25 nm. Also, the highly nonlinear lattice requires alignment of the multipole magnets to 30 microns. The speaker will describe the stability of the girder-magnets assembly and the factors affecting it, such as ambient ground motion and temperature fluctuations in the storage ring. Technical solutions to achieve the desired stability will be presented as well.
	Slides THOBS2 [4.431 MB]

MOP276	Applying Cascaded Parameter Scan to Study Top-off Safety in NSLS-II Storage Ring	627
	Y. Li, S.V. Badea, W.R. Casey, G. Ganetis, R. Heese, H.-C. Hseuh, P.K. Job, S. Krinsky, B. Parker, T.V. Shaftan, S.K. Sharma, L. Yang BNL, Upton, Long Island, New York, USA
	Funding: Work supported by U.S. DOE, Contract No. DE-AC02-98CH10886 In this paper we introduce a new algorithm, the cascaded parameter scan method, to efficiently carry out the scan over magnet parameters in the safety analysis for the NSLS-II top-off injection. In top-off safety analysis, one must track particles populating phase space through a beamline containing magnets and apertures and clearly demonstrate that for all possible magnet settings and errors, all particles are lost on scrapers within the properly shielded region. In the usual approach, the number of tracking runs increases exponentially with the number of magnet settings. In the cascaded parameter scan method, the number of tracking runs only increases linearly. This reduction of exponential to linear dependence on the number of setpoints, greatly reduces the required computation time and allows one to more densely populate phase space and to increase the number of setpoints scanned for each magnet. An example of applying this approach to analyze an NSLS-II beamline, the damping wiggler beamline, is also given.

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.

WEP201	Status of NSLS-II Booster	1864
	S.M. Gurov, A. Akimov, O. Anchugov, A.M. Batrakov, E.A. Bekhtenev, O.V. Belikov, P.B. Cheblakov, V.P. Cherepanov, A.D. Chernyakin, V.G. Cheskidov, I.N. Churkin, A.N. Dubrovin, A. Erokhin, K. Gorchakov, S.E. Karnaev, G.V. Karpov, V.A. Kiselev, V.V. Kobets, V.V. Kolmogorov, V.M. Konstantinov, A.A. Korepanov, E.A. Kuper, V. Kuzminykh, E.B. Levichev, V.R. Mamkin, A.S. Medvedko, O.I. Meshkov, N. Nefedov, V.V. Neyfeld, I.N. Okunev, M. Petrichenkov, V.V. Petrov, A. Polyansky, D.N. Pureskin, A. Rakhimov, S.I. Ruvinsky, T.V. Rybitskaya, L.M. Schegolev, A.V. Semenov, D.V. Senkov, S.S. Serednyakov, S.V. Shiyankov, D.A. Shvedov, S.V. Sinyatkin, V.V. Smaluk, A.V. Sukhanov, L. Tsukanova, A.V. Utkin, K. Yaminov BINP SB RAS, Novosibirsk, Russia J.H. DeLong, R.P. Fliller, G. Ganetis, H.-C. Hseuh, I. Pinayev, T.V. Shaftan, S.K. Sharma, O. Singh, Y. Tian, F.J. Willeke BNL, Upton, Long Island, New York, USA P.A.E. Elkiaer Danfysik A/S, Jyllinge, Denmark
	The National Synchrotron Light Source II is a third generation light source under construction at Brookhaven National Laboratory. The project includes a highly optimized 3 GeV electron storage ring, linac pre-injector and full-energy booster-synchrotron. Budker Institute of Nuclear Physics builds booster for NSLS-II. The booster should accelerate the electron beam continuously and reliably from minimal 170 MeV injection energy to maximal energy of 3.15 GeV and average beam current of 20 mA. The booster shall be capable of multi-bunch and single bunch operation. This paper summarizes the status of NSLS-II booster and the main designed parameters.

THP216	Progress with NSLS-II Injection Straight Section Design	2528
	T.V. Shaftan, A. Blednykh, W.R. Casey, L.R. Dalesio, R. Faussete, M.J. Ferreira, R.P. Fliller, G. Ganetis, R. Heese, H.-C. Hseuh, P.K. Job, E.D. Johnson, B.N. Kosciuk, S. Kowalski, S.L. Kramer, D. Padrazo, B. Parker, I. Pinayev, S.K. Sharma, O. Singh, C.J. Spataro, G.M. Wang, F.J. Willeke BNL, Upton, Long Island, New York, USA
	Funding: This work is supported by U.S. DOE, Contract No.DE-AC02-98CH10886 NSLS-II injection straight section consists of the pulsed and DC/Slow bumps, septa system, beam trajectory correction and diagnostics systems. In this paper we discuss overall injection straight layout, preliminary element designs, specifications for the pulsed and DC magnets and their power supplies, vacuum devices and chambers and diagnostics devices.