2011 Particle Accelerator Conference - List of Authors (Jain, A.K.)

Paper

Title

Page

Magnetic Field Mapping and Integral Transfer Function Matching of the Prototype Dipoles for the NSLS-II at BNL

1112

P. He, M. Anerella, G. Ganetis, R.C. Gupta, A.K. Jain, P.N. Joshi, J. Skaritka, C.J. Spataro, P. Wanderer
BNL, Upton, Long Island, New York, USA

The National Synchrotron Light Source-II (NSLS-II) storage ring at Brookhaven National Laboratory (BNL) will be equipped with 54 dipole magnets having a gap of 35 mm, and 6 dipoles having a gap of 90 mm. The large aperture magnets are necessary to allow the extraction of long-wavelength light from the dipole magnet to serve a growing number of users of low energy radiation. The dipoles must not only have good field homogeneity (0.015% over a 40 mm x 20 mm region), but the integral transfer functions and integral end harmonics of the two types of magnets must also be matched. The 35 mm aperture dipole has a novel design where the yoke ends are extended up to the outside dimension of the coil using magnetic steel nose pieces. A Hall probe mapping system has been built with three Group 3 Hall probes mounted on a 2-D translation stage. The probes are arranged with one probe in the midplane of the magnet and the others vertically offset by ±10 mm. The field is mapped along a nominal 25 m radius beam trajectory. The results of measurements in the as-received magnets, and with modifications made to the nose pieces will be presented.

TUP164

Magnetic Design of e-lens Solenoid and Corrector System for RHIC

1130

R.C. Gupta, M. Anerella, W. Fischer, G. Ganetis, A.K. Ghosh, X. Gu, A.K. Jain, P. Kovach, A. Marone, A.I. Pikin, S.R. Plate, P. Wanderer
BNL, Upton, Long Island, New York, USA

Funding: This work is supported by the U.S. Department of Energy under Contract No. DE-AC02-98CH10886.
As a part of the proposed electron lens system for RHIC, two 6 T, 200 mm aperture, 2.5 meter long superconducting solenoids are being designed and built at BNL. Because of several demanding requirements this has become a unique and technologically advanced magnet. For example, the field lines on axis must be straight over the length of the solenoid within ±50 microns. Since this is beyond the normal construction techniques, a correction package becomes an integral part of the design for which a new design has been developed. In addition, a minimum of 0.3 T field is required along the electron beam trajectory in the space between magnets. To achieve this fringe field superconducting solenoidal coils have been added at the two ends of the main solenoid. The main solenoid itself is a challenging magnet because of the high Lorentz forces and stored energy associated with the large aperture and high fields. An innovative structure has been developed to deal with the large axial forces at the ends. This paper will summarize the magnetic design and optimization of the entire package consisting of the main solenoid, the fringe field solenoids, and the corrector system.

WEP017

Re-Examination of the NSLS-II Magnet Multipole Specifications

1531

W. Guo, A.K. Jain, S. Krinsky, S. Seiler, J. Skaritka, C.J. Spataro
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy
The NSLS-II magnet multipole specifications were determined based on analysis of nonlinear beam dynamics. The required field quality does not exceed what was specified for the existing third-generation light sources. While the prototype magnets have met these specifications, the magnets from mass production could potentially have bigger errors which exceed certain tolerances. In this paper we discuss the results of recent calculations to provide further insight into the acceptable range of the magnet multipoles based on the physics requirements.

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]

THP006

Status of High Current R&D Energy Recovery Linac at Brookhaven National Laboratory

2148

D. Kayran, Z. Altinbas, D.R. Beavis, I. Ben-Zvi, R. Calaga, D.M. Gassner, H. Hahn, L.R. Hammons, A.K. Jain, J.P. Jamilkowski, N. Laloudakis, R.F. Lambiase, D.L. Lederle, V. Litvinenko, G.J. Mahler, G.T. McIntyre, W. Meng, B. Oerter, D. Pate, D. Phillips, J. Reich, T. Roser, C. Schultheiss, B. Sheehy, T. Srinivasan-Rao, R. Than, J.E. Tuozzolo, D. Weiss, W. Xu, A. Zaltsman
BNL, Upton, Long Island, New York, USA

An ampere-class 20 MeV superconducting energy recovery linac (ERL) is under construction at Brookhaven National Laboratory (BNL) for testing of concepts relevant for high-energy coherent electron cooling and electron-ion colliders. One of the goals is to demonstrate an electron beam with high charge per bunch (~5 nC) and low normalized emittance (~5 mm-mrad) at an energy of 20 MeV. A flexible lattice for the ERL loop provides a test bed for investigating issues of transverse and longitudinal instabilities and diagnostics for CW beam. A superconducting 703 MHz RF photo-injector is considered as an electron source for such a facility. We will start with a straight pass (gun/cavity/beam stop) test for gun performance studies. Later, we will install and test a novel injection line concept for emittance preservation in a lower-energy merger. Here we present the status and our plans for construction and commissioning of this facility.

THP055

Status of the RHIC Head-on Beam-beam Compensation Project

2223

W. Fischer, M. Anerella, E.N. Beebe, D. Bruno, D.M. Gassner, X. Gu, R.C. Gupta, J. Hock, A.K. Jain, R.F. Lambiase, C. Liu, Y. Luo, M. Mapes, T.A. Miller, C. Montag, B. Oerter, M. Okamura, A.I. Pikin, D. Raparia, Y. Tan, R. Than, P. Thieberger, J.E. Tuozzolo, W. Zhang
BNL, Upton, Long Island, New York, USA

Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886 with the U.S. Department of Energy.
Two electron lenses are under construction for RHIC to partially compensate the head-on beam-beam effect in order to increase both the peak and average luminosity. The final design of the overall system is reported as well as the status of the component design, acquisition, and manufacturing.

THP061

Mimicking Bipolar Sextupole Power Supplies for Low-energy Operations at RHIC

2241

C. Montag, D. Bruno, A.K. Jain, G. Robert-Demolaize, T. Satogata, S. Tepikian
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
RHIC operated at energies below the nominal ion injection energy of E=9.8 GeV/u in 2010. Earlier test runs and magnet measurements indicated that all defocusing sextupole unipolar power supplies should be reversed to provide the proper sign of chromaticity. However, vertical chromaticity at E=3.85 GeV/u with this power supply configuration was still not optimal. This uncertainty inspired a new machine configuration where only half of the defocusing sextupole power supplies were reversed, taking advantage of the flexibility of the RHIC nonlinear chromaticity correction system to mimic bipolar sextupoles. This configuration resulted in a 30 percent luminosity gain and eliminated the need for further polarity changes for later 2010 low energy physics operations. Here we describe the background to this problem, operational experience, and RHIC online model changes to implement this solution.

THP064

The Dipole Corrector Magnets for the RHIC Fast Global Orbit Feedback System

2249

P. Thieberger, L. Arnold, C. Folz, R.L. Hulsart, A.K. Jain, R. Karl, G.J. Mahler, W. Meng, K. Mernick, R.J. Michnoff, M.G. Minty, C. Montag, V. Ptitsyn, J. Ritter, L. Smart, J.E. Tuozzolo, J. White
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The recently completed RHIC fast global orbit feedback system uses 24 small “window-frame” horizontal dipole correctors. Space limitations dictated a very compact design. The magnetic design and modelling of these laminated yoke magnets is described as well as the mechanical implementation, coil winding, vacuum impregnation, etc. Test procedures to determine the field quality and frequency response are described. The results of these measurements are presented and discussed. A small fringe field from each magnet, overlapping the opposite RHIC ring, is compensated by a correction winding placed on the opposite ring’s magnet and connected in series with the main winding of the first one. Results from measurements of this compensation scheme are shown and discussed.

TUOAN2

High Luminosity Electron-Hadron Collider eRHIC

693

V. Ptitsyn, E.C. Aschenauer, M. Bai, J. Beebe-Wang, S.A. Belomestnykh, I. Ben-Zvi, M. Blaskiewicz, R. Calaga, X. Chang, A.V. Fedotov, H. Hahn, L.R. Hammons, Y. Hao, P. He, W.A. Jackson, A.K. Jain, E.C. Johnson, D. Kayran, J. Kewisch, V. Litvinenko, G.J. Mahler, G.T. McIntyre, W. Meng, M.G. Minty, B. Parker, A.I. Pikin, T. Rao, T. Roser, B. Sheehy, J. Skaritka, S. Tepikian, R. Than, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, G. Wang, Q. Wu, W. Xu, A. Zelenski
BNL, Upton, Long Island, New York, USA
E. Pozdeyev
FRIB, East Lansing, Michigan, USA
E. Tsentalovich
MIT, Middleton, Massachusetts, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
We present the design of future high-energy high-luminosity electron-hadron collider at RHIC called eRHIC. We plan on adding 20 (potentially 30) GeV energy recovery linacs to accelerate and to collide polarized and unpolarized electrons with hadrons in RHIC. The center-of-mass energy of eRHIC will range from 30 to 200 GeV. The luminosity exceeding 10³⁴ cm^-2 s^-1 can be achieved in eRHIC using the low-beta interaction region with a 10 mrad crab crossing. We report on the progress of important eRHIC R&D such as the high-current polarized electron source, the coherent electron cooling and the compact magnets for recirculating passes. A natural staging scenario of step-by-step increases of the electron beam energy by builiding-up of eRHIC's SRF linacs and a potential of adding polarized positrons are also presented.

Slides TUOAN2 [4.244 MB]

Paper	Title	Page
TUP149	Magnetic Field Mapping and Integral Transfer Function Matching of the Prototype Dipoles for the NSLS-II at BNL	1112
	P. He, M. Anerella, G. Ganetis, R.C. Gupta, A.K. Jain, P.N. Joshi, J. Skaritka, C.J. Spataro, P. Wanderer BNL, Upton, Long Island, New York, USA
	The National Synchrotron Light Source-II (NSLS-II) storage ring at Brookhaven National Laboratory (BNL) will be equipped with 54 dipole magnets having a gap of 35 mm, and 6 dipoles having a gap of 90 mm. The large aperture magnets are necessary to allow the extraction of long-wavelength light from the dipole magnet to serve a growing number of users of low energy radiation. The dipoles must not only have good field homogeneity (0.015% over a 40 mm x 20 mm region), but the integral transfer functions and integral end harmonics of the two types of magnets must also be matched. The 35 mm aperture dipole has a novel design where the yoke ends are extended up to the outside dimension of the coil using magnetic steel nose pieces. A Hall probe mapping system has been built with three Group 3 Hall probes mounted on a 2-D translation stage. The probes are arranged with one probe in the midplane of the magnet and the others vertically offset by ±10 mm. The field is mapped along a nominal 25 m radius beam trajectory. The results of measurements in the as-received magnets, and with modifications made to the nose pieces will be presented.

TUP164	Magnetic Design of e-lens Solenoid and Corrector System for RHIC	1130
	R.C. Gupta, M. Anerella, W. Fischer, G. Ganetis, A.K. Ghosh, X. Gu, A.K. Jain, P. Kovach, A. Marone, A.I. Pikin, S.R. Plate, P. Wanderer BNL, Upton, Long Island, New York, USA
	Funding: This work is supported by the U.S. Department of Energy under Contract No. DE-AC02-98CH10886. As a part of the proposed electron lens system for RHIC, two 6 T, 200 mm aperture, 2.5 meter long superconducting solenoids are being designed and built at BNL. Because of several demanding requirements this has become a unique and technologically advanced magnet. For example, the field lines on axis must be straight over the length of the solenoid within ±50 microns. Since this is beyond the normal construction techniques, a correction package becomes an integral part of the design for which a new design has been developed. In addition, a minimum of 0.3 T field is required along the electron beam trajectory in the space between magnets. To achieve this fringe field superconducting solenoidal coils have been added at the two ends of the main solenoid. The main solenoid itself is a challenging magnet because of the high Lorentz forces and stored energy associated with the large aperture and high fields. An innovative structure has been developed to deal with the large axial forces at the ends. This paper will summarize the magnetic design and optimization of the entire package consisting of the main solenoid, the fringe field solenoids, and the corrector system.

WEP017	Re-Examination of the NSLS-II Magnet Multipole Specifications	1531
	W. Guo, A.K. Jain, S. Krinsky, S. Seiler, J. Skaritka, C.J. Spataro BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy The NSLS-II magnet multipole specifications were determined based on analysis of nonlinear beam dynamics. The required field quality does not exceed what was specified for the existing third-generation light sources. While the prototype magnets have met these specifications, the magnets from mass production could potentially have bigger errors which exceed certain tolerances. In this paper we discuss the results of recent calculations to provide further insight into the acceptable range of the magnet multipoles based on the physics requirements.

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]

THP006	Status of High Current R&D Energy Recovery Linac at Brookhaven National Laboratory	2148
	D. Kayran, Z. Altinbas, D.R. Beavis, I. Ben-Zvi, R. Calaga, D.M. Gassner, H. Hahn, L.R. Hammons, A.K. Jain, J.P. Jamilkowski, N. Laloudakis, R.F. Lambiase, D.L. Lederle, V. Litvinenko, G.J. Mahler, G.T. McIntyre, W. Meng, B. Oerter, D. Pate, D. Phillips, J. Reich, T. Roser, C. Schultheiss, B. Sheehy, T. Srinivasan-Rao, R. Than, J.E. Tuozzolo, D. Weiss, W. Xu, A. Zaltsman BNL, Upton, Long Island, New York, USA
	An ampere-class 20 MeV superconducting energy recovery linac (ERL) is under construction at Brookhaven National Laboratory (BNL) for testing of concepts relevant for high-energy coherent electron cooling and electron-ion colliders. One of the goals is to demonstrate an electron beam with high charge per bunch (~5 nC) and low normalized emittance (~5 mm-mrad) at an energy of 20 MeV. A flexible lattice for the ERL loop provides a test bed for investigating issues of transverse and longitudinal instabilities and diagnostics for CW beam. A superconducting 703 MHz RF photo-injector is considered as an electron source for such a facility. We will start with a straight pass (gun/cavity/beam stop) test for gun performance studies. Later, we will install and test a novel injection line concept for emittance preservation in a lower-energy merger. Here we present the status and our plans for construction and commissioning of this facility.

THP055	Status of the RHIC Head-on Beam-beam Compensation Project	2223
	W. Fischer, M. Anerella, E.N. Beebe, D. Bruno, D.M. Gassner, X. Gu, R.C. Gupta, J. Hock, A.K. Jain, R.F. Lambiase, C. Liu, Y. Luo, M. Mapes, T.A. Miller, C. Montag, B. Oerter, M. Okamura, A.I. Pikin, D. Raparia, Y. Tan, R. Than, P. Thieberger, J.E. Tuozzolo, W. Zhang BNL, Upton, Long Island, New York, USA
	Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886 with the U.S. Department of Energy. Two electron lenses are under construction for RHIC to partially compensate the head-on beam-beam effect in order to increase both the peak and average luminosity. The final design of the overall system is reported as well as the status of the component design, acquisition, and manufacturing.

THP061	Mimicking Bipolar Sextupole Power Supplies for Low-energy Operations at RHIC	2241
	C. Montag, D. Bruno, A.K. Jain, G. Robert-Demolaize, T. Satogata, S. Tepikian BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. RHIC operated at energies below the nominal ion injection energy of E=9.8 GeV/u in 2010. Earlier test runs and magnet measurements indicated that all defocusing sextupole unipolar power supplies should be reversed to provide the proper sign of chromaticity. However, vertical chromaticity at E=3.85 GeV/u with this power supply configuration was still not optimal. This uncertainty inspired a new machine configuration where only half of the defocusing sextupole power supplies were reversed, taking advantage of the flexibility of the RHIC nonlinear chromaticity correction system to mimic bipolar sextupoles. This configuration resulted in a 30 percent luminosity gain and eliminated the need for further polarity changes for later 2010 low energy physics operations. Here we describe the background to this problem, operational experience, and RHIC online model changes to implement this solution.

THP064	The Dipole Corrector Magnets for the RHIC Fast Global Orbit Feedback System	2249
	P. Thieberger, L. Arnold, C. Folz, R.L. Hulsart, A.K. Jain, R. Karl, G.J. Mahler, W. Meng, K. Mernick, R.J. Michnoff, M.G. Minty, C. Montag, V. Ptitsyn, J. Ritter, L. Smart, J.E. Tuozzolo, J. White BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The recently completed RHIC fast global orbit feedback system uses 24 small “window-frame” horizontal dipole correctors. Space limitations dictated a very compact design. The magnetic design and modelling of these laminated yoke magnets is described as well as the mechanical implementation, coil winding, vacuum impregnation, etc. Test procedures to determine the field quality and frequency response are described. The results of these measurements are presented and discussed. A small fringe field from each magnet, overlapping the opposite RHIC ring, is compensated by a correction winding placed on the opposite ring’s magnet and connected in series with the main winding of the first one. Results from measurements of this compensation scheme are shown and discussed.

TUOAN2	High Luminosity Electron-Hadron Collider eRHIC	693
	V. Ptitsyn, E.C. Aschenauer, M. Bai, J. Beebe-Wang, S.A. Belomestnykh, I. Ben-Zvi, M. Blaskiewicz, R. Calaga, X. Chang, A.V. Fedotov, H. Hahn, L.R. Hammons, Y. Hao, P. He, W.A. Jackson, A.K. Jain, E.C. Johnson, D. Kayran, J. Kewisch, V. Litvinenko, G.J. Mahler, G.T. McIntyre, W. Meng, M.G. Minty, B. Parker, A.I. Pikin, T. Rao, T. Roser, B. Sheehy, J. Skaritka, S. Tepikian, R. Than, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, G. Wang, Q. Wu, W. Xu, A. Zelenski BNL, Upton, Long Island, New York, USA E. Pozdeyev FRIB, East Lansing, Michigan, USA E. Tsentalovich MIT, Middleton, Massachusetts, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. We present the design of future high-energy high-luminosity electron-hadron collider at RHIC called eRHIC. We plan on adding 20 (potentially 30) GeV energy recovery linacs to accelerate and to collide polarized and unpolarized electrons with hadrons in RHIC. The center-of-mass energy of eRHIC will range from 30 to 200 GeV. The luminosity exceeding 10³⁴ cm^-2 s^-1 can be achieved in eRHIC using the low-beta interaction region with a 10 mrad crab crossing. We report on the progress of important eRHIC R&D such as the high-current polarized electron source, the coherent electron cooling and the compact magnets for recirculating passes. A natural staging scenario of step-by-step increases of the electron beam energy by builiding-up of eRHIC's SRF linacs and a potential of adding polarized positrons are also presented.
	Slides TUOAN2 [4.244 MB]