IPAC2015 - List of Authors (Fischer, W.)

Paper	Title	Page
TUPWI047	Target and Orbit Feedback Simulations of a muSR Beamline at BNL	2353
	W. Fischer, M. Blaskiewicz, P.H. Pile BNL, Upton, Long Island, New York, USA W.W. MacKay Weirich Consulting Services, Inc., Huntersville, North Carolina, USA
	Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886 with the U.S. Department of Energy. Well-polarized positive surface muons are a tool to measure the magnetic properties of materials since the precession rate of the spin can be determined from the observation of the positron directions when the muons decay. The use of the AGS complex at BNL has been explored for a muSR facility previously. Here we report simulations of a beamline with a target inside a solenoid, and of an orbit feedback system with single muon beam positioning monitors based on technology available today.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPWI047
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TUPWI060	RHIC Polarized Proton-Proton Operation at 100 GeV in Run 15	2384
	V. Schoefer, E.C. Aschenauer, G. Atoian, M. Blaskiewicz, K.A. Brown, D. Bruno, R. Connolly, T. D'Ottavio, K.A. Drees, Y. Dutheil, W. Fischer, C.J. Gardner, X. Gu, T. Hayes, H. Huang, J.S. Laster, C. Liu, Y. Luo, Y. Makdisi, G.J. Marr, A. Marusic, F. Méot, K. Mernick, R.J. Michnoff, M.G. Minty, C. Montag, J. Morris, S. Nemesure, P.H. Pile, A. Poblaguev, V.H. Ranjbar, G. Robert-Demolaize, T. Roser, W.B. Schmidke, F. Severino, T.C. Shrey, K.S. Smith, D. Steski, S. Tepikian, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, G. Wang, S.M. White, K. Yip, A. Zaltsman, A. Zelenski, K. Zeno, S.Y. Zhang BNL, Upton, Long Island, New York, USA
	The first part of RHIC Run 15 consisted of nine weeks of polarized proton on proton collisions at a beam energy of 100 GeV at two interaction points. In this paper we discuss several of the upgrades to the collider complex that allowed for improved performance this run. The largest effort consisted of commissioning of the electron lenses, one in each ring, which are designed to compensate one of the two beam-beam interactions experienced by the proton bunches. The e-lenses therefore raise the per bunch intensity at which luminosity becomes beam-beam limited. A new lattice was designed to create the phase advances necessary for a functioning e-lens which also has an improved off-momentum dynamic aperture relative to previous runs. In order to take advantage of the new, higher intensity limit without suffering intensity driven emittance deterioration, other features were commissioned including a continuous transverse bunch-by-bunch damper in RHIC and a double harmonic capture scheme in the Booster. Other high intensity protections include improvements to the abort system and the installation of masks to intercept beam lost due to abort kicker pre-fires.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPWI060
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WEPWI054	Design and Test of the RHIC CMD10 Abort Kicker	3612
	H. Hahn, M. Blaskiewicz, K.A. Drees, W. Fischer, W. Meng, J.-L. Mi, C. Montag, C. Pai, J. Sandberg, N. Tsoupas, J.E. Tuozzolo, W. Zhang 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. Planned and unplanned thyratron pre-fire triggered beam dumps have been observed in the yellow ring that were associated with quenches of the superconducting main ring magnets as the proton intensities increased in the FY10¹³ run. The increasing vacuum level indicated beam induced kicker ferrite heating causing lower magnetic kick field at a nominal pulse current. In anticipation of higher current and shorter bunches in FY2015 an accelerator improvement program was initiated to reduce the longitudinal coupling impedance with changes to the eddy-current strip geometry using Opera simulations and to change the CMD5005 to CMD10 ferrite. Results of the standard impedance measurements and of pulse current in heating tests to 170 °C are reported. All 10 dump kickers are being modified and are encapsulated with a cooling system for installation in the rings.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWI054
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THPF046	Operation of the RHIC Injector Chain with Ions from EBIS	3804
	C.J. Gardner, J.G. Alessi, E.N. Beebe, I. Blackler, M. Blaskiewicz, J.M. Brennan, K.A. Brown, J.J. Butler, C. Carlson, W. Fischer, D.M. Gassner, D. Goldberg, T. Hayes, H. Huang, P.F. Ingrassia, J.P. Jamilkowski, N.A. Kling, J.S. Laster, D. Maffei, M. Mapes, I. Marneris, G.J. Marr, A. Marusic, D.R. McCafferty, K. Mernick, M.G. Minty, J. Morris, C. Naylor, S. Nemesure, S. Perez, A.I. Pikin, D. Raparia, T. Roser, P. Sampson, J. Sandberg, V. Schoefer, F. Severino, T.C. Shrey, K.S. Smith, D. Steski, P. Thieberger, J.E. Tuozzolo, B. Van Kuik, A. Zaltsman, K. Zeno, W. Zhang 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. Since 2012 gold and all other ions for the RHIC injector chain have been provided by an Electron Beam Ion Source (EBIS). The source is followed by an RFQ, a short Linac, and a 30 m transport line. These components replace the Tandem van de Graaff and associated 840 m transfer line. They provide ions at 2 MeV per nucleon (kinetic energy) for injection into the AGS Booster. The setup and operation of Booster and AGS with various ions from the new source are reviewed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF046
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THPF059	RHIC Electron Lenses Upgrades	3830
	X. Gu, Z. Altinbas, S. Binello, D. Bruno, M.R. Costanzo, K.A. Drees, W. Fischer, D.M. Gassner, M. Harvey, J. Hock, K. Hock, Y. Luo, A. Marusic, K. Mernick, C. Mi, R.J. Michnoff, T.A. Miller, M.G. Minty, A.I. Pikin, G. Robert-Demolaize, T. Samms, V. Schoefer, T.C. Shrey, Y. Tan, R. Than, P. Thieberger BNL, Upton, Long Island, New York, USA S.M. White ESRF, Grenoble, France
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. In the Relativistic Heavy Ion Collider (RHIC) 100 GeV polarized proton run in 2015[1], two electron lenses [2] were used for the first time to partially compensate for the head-on beam-beam effect. Here, we describe the design of the current electron lens, detailing the hardware modifications made after the 2014 commissioning run with heavy ions. A new electron gun with 15-mm diameter cathode is characterized. The electron beam transverse profile was measured using a YAG screen and fitted with a Gaussian distribution. During operation, the overlap of the electron and proton beams was achieved using the electron backscattering detector in conjunction with an automated orbit control program.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF059
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Paper

Title

Page

Target and Orbit Feedback Simulations of a muSR Beamline at BNL

2353

W. Fischer, M. Blaskiewicz, P.H. Pile
BNL, Upton, Long Island, New York, USA
W.W. MacKay
Weirich Consulting Services, Inc., Huntersville, North Carolina, USA

Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886 with the U.S. Department of Energy.
Well-polarized positive surface muons are a tool to measure the magnetic properties of materials since the precession rate of the spin can be determined from the observation of the positron directions when the muons decay. The use of the AGS complex at BNL has been explored for a muSR facility previously. Here we report simulations of a beamline with a target inside a solenoid, and of an orbit feedback system with single muon beam positioning monitors based on technology available today.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPWI047

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPWI060

RHIC Polarized Proton-Proton Operation at 100 GeV in Run 15

2384

V. Schoefer, E.C. Aschenauer, G. Atoian, M. Blaskiewicz, K.A. Brown, D. Bruno, R. Connolly, T. D'Ottavio, K.A. Drees, Y. Dutheil, W. Fischer, C.J. Gardner, X. Gu, T. Hayes, H. Huang, J.S. Laster, C. Liu, Y. Luo, Y. Makdisi, G.J. Marr, A. Marusic, F. Méot, K. Mernick, R.J. Michnoff, M.G. Minty, C. Montag, J. Morris, S. Nemesure, P.H. Pile, A. Poblaguev, V.H. Ranjbar, G. Robert-Demolaize, T. Roser, W.B. Schmidke, F. Severino, T.C. Shrey, K.S. Smith, D. Steski, S. Tepikian, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, G. Wang, S.M. White, K. Yip, A. Zaltsman, A. Zelenski, K. Zeno, S.Y. Zhang
BNL, Upton, Long Island, New York, USA

The first part of RHIC Run 15 consisted of nine weeks of polarized proton on proton collisions at a beam energy of 100 GeV at two interaction points. In this paper we discuss several of the upgrades to the collider complex that allowed for improved performance this run. The largest effort consisted of commissioning of the electron lenses, one in each ring, which are designed to compensate one of the two beam-beam interactions experienced by the proton bunches. The e-lenses therefore raise the per bunch intensity at which luminosity becomes beam-beam limited. A new lattice was designed to create the phase advances necessary for a functioning e-lens which also has an improved off-momentum dynamic aperture relative to previous runs. In order to take advantage of the new, higher intensity limit without suffering intensity driven emittance deterioration, other features were commissioned including a continuous transverse bunch-by-bunch damper in RHIC and a double harmonic capture scheme in the Booster. Other high intensity protections include improvements to the abort system and the installation of masks to intercept beam lost due to abort kicker pre-fires.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPWI060

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reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPWI054

Design and Test of the RHIC CMD10 Abort Kicker

3612

H. Hahn, M. Blaskiewicz, K.A. Drees, W. Fischer, W. Meng, J.-L. Mi, C. Montag, C. Pai, J. Sandberg, N. Tsoupas, J.E. Tuozzolo, W. Zhang
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.
Planned and unplanned thyratron pre-fire triggered beam dumps have been observed in the yellow ring that were associated with quenches of the superconducting main ring magnets as the proton intensities increased in the FY10¹³ run. The increasing vacuum level indicated beam induced kicker ferrite heating causing lower magnetic kick field at a nominal pulse current. In anticipation of higher current and shorter bunches in FY2015 an accelerator improvement program was initiated to reduce the longitudinal coupling impedance with changes to the eddy-current strip geometry using Opera simulations and to change the CMD5005 to CMD10 ferrite. Results of the standard impedance measurements and of pulse current in heating tests to 170 °C are reported. All 10 dump kickers are being modified and are encapsulated with a cooling system for installation in the rings.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWI054

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reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPF046

Operation of the RHIC Injector Chain with Ions from EBIS

3804

C.J. Gardner, J.G. Alessi, E.N. Beebe, I. Blackler, M. Blaskiewicz, J.M. Brennan, K.A. Brown, J.J. Butler, C. Carlson, W. Fischer, D.M. Gassner, D. Goldberg, T. Hayes, H. Huang, P.F. Ingrassia, J.P. Jamilkowski, N.A. Kling, J.S. Laster, D. Maffei, M. Mapes, I. Marneris, G.J. Marr, A. Marusic, D.R. McCafferty, K. Mernick, M.G. Minty, J. Morris, C. Naylor, S. Nemesure, S. Perez, A.I. Pikin, D. Raparia, T. Roser, P. Sampson, J. Sandberg, V. Schoefer, F. Severino, T.C. Shrey, K.S. Smith, D. Steski, P. Thieberger, J.E. Tuozzolo, B. Van Kuik, A. Zaltsman, K. Zeno, W. Zhang
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.
Since 2012 gold and all other ions for the RHIC injector chain have been provided by an Electron Beam Ion Source (EBIS). The source is followed by an RFQ, a short Linac, and a 30 m transport line. These components replace the Tandem van de Graaff and associated 840 m transfer line. They provide ions at 2 MeV per nucleon (kinetic energy) for injection into the AGS Booster. The setup and operation of Booster and AGS with various ions from the new source are reviewed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF046

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPF059

RHIC Electron Lenses Upgrades

3830

X. Gu, Z. Altinbas, S. Binello, D. Bruno, M.R. Costanzo, K.A. Drees, W. Fischer, D.M. Gassner, M. Harvey, J. Hock, K. Hock, Y. Luo, A. Marusic, K. Mernick, C. Mi, R.J. Michnoff, T.A. Miller, M.G. Minty, A.I. Pikin, G. Robert-Demolaize, T. Samms, V. Schoefer, T.C. Shrey, Y. Tan, R. Than, P. Thieberger
BNL, Upton, Long Island, New York, USA
S.M. White
ESRF, Grenoble, France

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
In the Relativistic Heavy Ion Collider (RHIC) 100 GeV polarized proton run in 2015[1], two electron lenses [2] were used for the first time to partially compensate for the head-on beam-beam effect. Here, we describe the design of the current electron lens, detailing the hardware modifications made after the 2014 commissioning run with heavy ions. A new electron gun with 15-mm diameter cathode is characterized. The electron beam transverse profile was measured using a YAG screen and fitted with a Gaussian distribution. During operation, the overlap of the electron and proton beams was achieved using the electron backscattering detector in conjunction with an automated orbit control program.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF059

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)