IPAC2012 - List of Authors (Spiller, P.J.)

Paper	Title	Page
TUPPC005	Optimization of the SIS100 Nonlinear Magnet Scheme for Slow Extraction	1158
	A. Saa Hernandez, M.M. Kirk, D. Ondreka, N. Pyka, S. Sorge, P.J. Spiller GSI, Darmstadt, Germany
	The SIS100 superconducting synchrotron was initially planned mainly for fast extraction of protons and heavy ions. Due to the delay of the construction of the SIS300 synchrotron, SIS100 has to be able to provide slowly extracted heavy ion beams to the experiments. To improve the robustness of the slow extraction from SIS100, a lattice review was performed, resulting in an optimization of the nonlinear magnet scheme. In the original scheme the Hardt condition cannot be established due to a collapse of the dynamic aperture caused by the chromatic sextupoles. In the optimized scheme the positions of the chromatic sextupoles are modified and octupoles are employed to compensate the second order effects of these sextupoles. In addition, the number of resonance sextupole magnets is reduced. With the new scheme, the Hardt condition can be established, leading to higher extraction efficiency. The separatrix can be freely adjusted, and closed orbit control is improved.

WEPPD028	Collimators and Materials for High Intensity Heavy Ion Synchrotrons	2564
	J. Stadlmann, H. Kollmus, P.J. Spiller, I. Strašík, N.A. Tahir, M. Tomut, C. Trautmann GSI, Darmstadt, Germany L.H.J. Bozyk TU Darmstadt, Darmstadt, Germany
	Funding: Funded by EU FP7 WP8 ColMat and Federal Republic of Germany The operation of high power high brightness accelerators requires huge efforts for beam cleaning and machine protection. Within the WP 8 (ColMat)of the EU research framework EuCARD we investigate new materials and methods for beam collimation and machine protection. TWe present an overview of these activities at the GSI Helmholtzzentrum für Schwerioneforschung in Darmstadt. Simulations of accidental beam losses in LHC and SIS100 have been performed. Scenarios for halo collimation of heavy ions and protons in SIS100 routine operation have been investigated. A prototype of a cryogenic collimator for charge exchange losses during intermediate charge state heavy ion operation in SIS100 has been build and tested with beam. Several candidates of advances composite materials for collimation system upgrades of present and construction of future high power accelerators have been irradiated and their properties are being characterized. Most deliverables and milestones of the R&D programm have already been reached before the end of the funding period. A summary of the obtained results will be presented.

THEPPB004	Development of a Cryocatcher-System for SIS100	3237
	L.H.J. Bozyk, H. Kollmus, P.J. Spiller GSI, Darmstadt, Germany
	Funding: Work supported by EU (FP7 workpackage COLMAT) and GP-HIR – Graduate Program for Hadron and Ion Research at GSI. The main accelerator SIS100 of the FAIR-facility will provide heavy ion beams of highest intensities using intermediate charge state heavy ions. Ionization beam loss is the most important loss mechanism, therefore, a special synchrotron layout has been developed, which includes a dedicated cold ion catcher system which provides almost hundred percent catching efficiency. Dynamic vacuum effects are suppressed effectively by means of special low desorption yield surfaces. A prototype of the cryocatcher system has been developed, constructed and tested with heavy ion beam from SIS18. It is a work package of the EU-FP-7 project COLMAT. Results from these tests are presented as well as implications for the production of the 60 SIS100 cryocatchers.

THPPP001	High Intensity Intermediate Charge State Heavy Ions in Synchrotrons	3719
	P.J. Spiller, U. Blell, L.H.J. Bozyk, H. Reich-Sprenger, J. Stadlmann GSI, Darmstadt, Germany Y. El-Hayek FIAS, Frankfurt am Main, Germany
	In order to reach the desired FAIR intensities for heavy ions, SIS18 and SIS100 have to be operated with intermediate charge states. Operation with intermediate charge state heavy ions at the intensity level of about 1011 ions per cycle has never been demonstrated elsewhere and requires a dedicated machine design. After partially completing the upgrade program of SIS18, the number of intermediate charge state heavy ions accelerated to the FAIR booster energy of 200 MeV/u, could be increased by a factor of 70. The specific challenge for the SIS18 and SIS100 booster operation is the high cross section for ionization of the intermediate charge state heavy ions, in combination with gas desorption processes and the dynamic vacuum pressure. The achieved progress in minimizing the ionization beam loss underlines that the chosen technical strategies described in this report are appropriate. The latest intensity records and results from the machine development programs are presented.

Paper

Title

Page

Optimization of the SIS100 Nonlinear Magnet Scheme for Slow Extraction

1158

A. Saa Hernandez, M.M. Kirk, D. Ondreka, N. Pyka, S. Sorge, P.J. Spiller
GSI, Darmstadt, Germany

The SIS100 superconducting synchrotron was initially planned mainly for fast extraction of protons and heavy ions. Due to the delay of the construction of the SIS300 synchrotron, SIS100 has to be able to provide slowly extracted heavy ion beams to the experiments. To improve the robustness of the slow extraction from SIS100, a lattice review was performed, resulting in an optimization of the nonlinear magnet scheme. In the original scheme the Hardt condition cannot be established due to a collapse of the dynamic aperture caused by the chromatic sextupoles. In the optimized scheme the positions of the chromatic sextupoles are modified and octupoles are employed to compensate the second order effects of these sextupoles. In addition, the number of resonance sextupole magnets is reduced. With the new scheme, the Hardt condition can be established, leading to higher extraction efficiency. The separatrix can be freely adjusted, and closed orbit control is improved.

WEPPD028

Collimators and Materials for High Intensity Heavy Ion Synchrotrons

2564

J. Stadlmann, H. Kollmus, P.J. Spiller, I. Strašík, N.A. Tahir, M. Tomut, C. Trautmann
GSI, Darmstadt, Germany
L.H.J. Bozyk
TU Darmstadt, Darmstadt, Germany

Funding: Funded by EU FP7 WP8 ColMat and Federal Republic of Germany
The operation of high power high brightness accelerators requires huge efforts for beam cleaning and machine protection. Within the WP 8 (ColMat)of the EU research framework EuCARD we investigate new materials and methods for beam collimation and machine protection. TWe present an overview of these activities at the GSI Helmholtzzentrum für Schwerioneforschung in Darmstadt. Simulations of accidental beam losses in LHC and SIS100 have been performed. Scenarios for halo collimation of heavy ions and protons in SIS100 routine operation have been investigated. A prototype of a cryogenic collimator for charge exchange losses during intermediate charge state heavy ion operation in SIS100 has been build and tested with beam. Several candidates of advances composite materials for collimation system upgrades of present and construction of future high power accelerators have been irradiated and their properties are being characterized. Most deliverables and milestones of the R&D programm have already been reached before the end of the funding period. A summary of the obtained results will be presented.

THEPPB004

Development of a Cryocatcher-System for SIS100

3237

L.H.J. Bozyk, H. Kollmus, P.J. Spiller
GSI, Darmstadt, Germany

Funding: Work supported by EU (FP7 workpackage COLMAT) and GP-HIR – Graduate Program for Hadron and Ion Research at GSI.
The main accelerator SIS100 of the FAIR-facility will provide heavy ion beams of highest intensities using intermediate charge state heavy ions. Ionization beam loss is the most important loss mechanism, therefore, a special synchrotron layout has been developed, which includes a dedicated cold ion catcher system which provides almost hundred percent catching efficiency. Dynamic vacuum effects are suppressed effectively by means of special low desorption yield surfaces. A prototype of the cryocatcher system has been developed, constructed and tested with heavy ion beam from SIS18. It is a work package of the EU-FP-7 project COLMAT. Results from these tests are presented as well as implications for the production of the 60 SIS100 cryocatchers.

THPPP001

High Intensity Intermediate Charge State Heavy Ions in Synchrotrons

3719

P.J. Spiller, U. Blell, L.H.J. Bozyk, H. Reich-Sprenger, J. Stadlmann
GSI, Darmstadt, Germany
Y. El-Hayek
FIAS, Frankfurt am Main, Germany

In order to reach the desired FAIR intensities for heavy ions, SIS18 and SIS100 have to be operated with intermediate charge states. Operation with intermediate charge state heavy ions at the intensity level of about 1011 ions per cycle has never been demonstrated elsewhere and requires a dedicated machine design. After partially completing the upgrade program of SIS18, the number of intermediate charge state heavy ions accelerated to the FAIR booster energy of 200 MeV/u, could be increased by a factor of 70. The specific challenge for the SIS18 and SIS100 booster operation is the high cross section for ionization of the intermediate charge state heavy ions, in combination with gas desorption processes and the dynamic vacuum pressure. The achieved progress in minimizing the ionization beam loss underlines that the chosen technical strategies described in this report are appropriate. The latest intensity records and results from the machine development programs are presented.