IPAC2013 - List of Authors (Burkart, F.)

Paper

Title

Page

Results of an Experiment on Hydrodynamic Tunnelling at the SPS HiRadMat High Intensity Proton Facility

37

R. Schmidt, J. Blanco, F. Burkart, D. Grenier, D. Wollmann
CERN, Geneva, Switzerland
E. Griesmayer
CIVIDEC Instrumentation, Wien, Austria
N.A. Tahir
GSI, Darmstadt, Germany

To predict the damage for a catastrophic failure of the protections systems for the LHC when operating with beams storing 362 MJ, simulation studies of the impact of an LHC beam on targets were performed. Firstly, the energy deposition of the first bunches in a target with FLUKA is calculated. The effect of the energy deposition on the target is then calculated with a hydrodynamic code, BIG2. The impact of only a few bunches leads to a change of target density. The calculations are done iteratively in several steps and show that such beam can tunnel up to 30-35 m into a target. Validation experiments for these calculations at LHC are not possible, therefore experiments were suggested for the CERN Super Proton Synchrotron (SPS), since simulation studies with the tools used for the LHC also predict hydrodynamic tunnelling for SPS beams. An experiment at the SPS-HiRadMat facility (High-Radiation to Materials) using the 440 GeV beam with 144 bunches was performed in July 2012. In this paper we compare the results of this experiment with our calculations of hydrodynamic tunnelling.

Slides MOODB103 [40.426 MB]

MOPWO039

Experience with High-intensity Beam Scraping and Tail Populations at the Large Hadon Collider

978

S. Redaelli, R. Bruce, F. Burkart, D. Mirarchi, B. Salvachua, G. Valentino, D. Wollmann
CERN, Geneva, Switzerland
R.W. Aßmann
DESY, Hamburg, Germany
G. Valentino
University of Malta, Information and Communication Technology, Msida, Malta

The population of beam tails at the LHC is source of concern because even small fractions of the total beam intensity could represent a potential danger is case of slow or fast losses, e.g. caused by orbit transients or by collimator movements. Different studies have been performed using the technique of collimator scans to probe the beam tail population, for different beam energies and beam intensities. The experience accumulated during the operation at 3.5 TeV and 4 TeV is reviewed and extrapolations to higher energies are considered.

MOPWO049

Lifetime Analysis at High Intensity Colliders Applied to the LHC

1005

B. Salvachua, R.W. Aßmann, R. Bruce, F. Burkart, S. Redaelli, G. Valentino, D. Wollmann
CERN, Geneva, Switzerland
G. Valentino
University of Malta, Information and Communication Technology, Msida, Malta

The beam lifetime is one of the main parameters to define the performance of a collider. In a super-conducting machine like the LHC, the lifetime determines the intensity reach for a given collimation cleaning. The beam lifetime can be calculated from the direct measurement of beam current. However, due to the noise in the beam current signal only an average lifetime over several seconds can be calculated. We propose here an alternative method, which uses the signal of the beam loss monitors in the vicinity of the primary collimators to get the instantaneous beam lifetime at the collimators. In this paper we compare the lifetime from the two methods and investigate the minimum lifetime over the LHC cycle for all the physics fills in 2011 and 2012. These data provide a reference for estimates of performance reach from collimator cleaning.

THPEA047

Diamond Particle Detector Properties during High Fluence Material Damage Tests and their Future Applications for Machine Protection in the LHC

3249

F. Burkart, J. Blanco, J. Borburgh, B. Dehning, M. Di Castro, E. Griesmayer, A. Lechner, J. Lendaro, F. Loprete, R. Losito, S. Montesano, R. Schmidt, D. Wollmann, M. Zerlauth
CERN, Geneva, Switzerland
E. Griesmayer
CIVIDEC Instrumentation, Wien, Austria

Experience with LHC machine protection (MP) during the last three years of operation shows that the MP systems sufficiently protect the LHC against damage in case of failures leading to beam losses with a time constant exceeding 1ms. An unexpected fast beam loss mechanism, called UFOs, was observed, which could potentially quench superconducting magnets. For such fast losses, but also for better understanding of slower losses, an improved understanding of the loss distribution within a bunch train is required. Diamond particle detectors with bunch-by-bunch resolution and high dynamic range have been developed and successfully tested in the LHC and in experiments to quantify the damage limits of LHC components. This paper will focus on experience gained in use of diamond detectors. The properties of these detectors were measured during high-fluence material damage tests in CERN's HiRadMat facility. The results will be discussed and compared to the cross-calibration with FLUKA simulations. Future applications of these detectors in the LHC to understand beam losses and to improve the protection against fast particle losses will be discussed.

THPFI059

Robustness Test of a Silicon Strip Crystal for Crystal-assisted Collimation Studies in the LHC

3427

A. Lechner, J. Blanco Sancho, F. Burkart, M. Calviani, M. Di Castro, Y. Gavrikov, J. Lendaro, F. Loprete, R. Losito, C. Maglioni, A. Masi, S. Montesano, A. Perillo-Marcone, P.S. Roguet, W. Scandale, D. Wollmann
CERN, Geneva, Switzerland
J. Blanco Sancho
EPFL, Lausanne, Switzerland
F. Burkart
IAP, Frankfurt am Main, Germany
Y. Gavrikov
PNPI, Gatchina, Leningrad District, Russia
V. Guidi, A. Mazzolari
INFN-Ferrara, Ferrara, Italy
V. Guidi, A. Mazzolari
UNIFE, Ferrara, Italy
W. Scandale
LAL, Orsay, France

Over the past years, the UA9 experiment has successfully demonstrated the viability of enhancing the collimation efficiency of proton and ion beams in the SPS by means of bent crystals. An extension of UA9 to the LHC has been recently approved. The conditions imposed by the LHC operational environment, in particular the tremendous energy density of the beam, require a reliable understanding of the crystal integrity in view of potential accident scenarios such as an asynchronous beam dump. For this purpose, irradiation tests have been performed at the CERN-HiRadMat facility to examine the mechanical strength of a silicon strip crystal in case of direct beam impact. The tests were carried out using a 440 GeV proton beam of 0.5 mm transverse size. The crystal, 3 mm long in beam direction, was exposed to a total of 2*10¹⁴ protons, with individual pulse intensities reaching up to 3*10¹³. First visual inspections reveal no macroscopic damage to the crystal. Complementary post-irradiation tests are foreseen to assess microscopic lattice damage as well as the degradation of the channelling efficiency.
On behalf of the UA9 Collaboration.

THPFI059

Robustness Test of a Silicon Strip Crystal for Crystal-assisted Collimation Studies in the LHC

3427

A. Lechner, J. Blanco Sancho, F. Burkart, M. Calviani, M. Di Castro, Y. Gavrikov, J. Lendaro, F. Loprete, R. Losito, C. Maglioni, A. Masi, S. Montesano, A. Perillo-Marcone, P.S. Roguet, W. Scandale, D. Wollmann
CERN, Geneva, Switzerland
J. Blanco Sancho
EPFL, Lausanne, Switzerland
F. Burkart
IAP, Frankfurt am Main, Germany
Y. Gavrikov
PNPI, Gatchina, Leningrad District, Russia
V. Guidi, A. Mazzolari
INFN-Ferrara, Ferrara, Italy
V. Guidi, A. Mazzolari
UNIFE, Ferrara, Italy
W. Scandale
LAL, Orsay, France

Over the past years, the UA9 experiment has successfully demonstrated the viability of enhancing the collimation efficiency of proton and ion beams in the SPS by means of bent crystals. An extension of UA9 to the LHC has been recently approved. The conditions imposed by the LHC operational environment, in particular the tremendous energy density of the beam, require a reliable understanding of the crystal integrity in view of potential accident scenarios such as an asynchronous beam dump. For this purpose, irradiation tests have been performed at the CERN-HiRadMat facility to examine the mechanical strength of a silicon strip crystal in case of direct beam impact. The tests were carried out using a 440 GeV proton beam of 0.5 mm transverse size. The crystal, 3 mm long in beam direction, was exposed to a total of 2*10¹⁴ protons, with individual pulse intensities reaching up to 3*10¹³. First visual inspections reveal no macroscopic damage to the crystal. Complementary post-irradiation tests are foreseen to assess microscopic lattice damage as well as the degradation of the channelling efficiency.
On behalf of the UA9 Collaboration.

Paper	Title	Page
MOODB103	Results of an Experiment on Hydrodynamic Tunnelling at the SPS HiRadMat High Intensity Proton Facility	37
	R. Schmidt, J. Blanco, F. Burkart, D. Grenier, D. Wollmann CERN, Geneva, Switzerland E. Griesmayer CIVIDEC Instrumentation, Wien, Austria N.A. Tahir GSI, Darmstadt, Germany
	To predict the damage for a catastrophic failure of the protections systems for the LHC when operating with beams storing 362 MJ, simulation studies of the impact of an LHC beam on targets were performed. Firstly, the energy deposition of the first bunches in a target with FLUKA is calculated. The effect of the energy deposition on the target is then calculated with a hydrodynamic code, BIG2. The impact of only a few bunches leads to a change of target density. The calculations are done iteratively in several steps and show that such beam can tunnel up to 30-35 m into a target. Validation experiments for these calculations at LHC are not possible, therefore experiments were suggested for the CERN Super Proton Synchrotron (SPS), since simulation studies with the tools used for the LHC also predict hydrodynamic tunnelling for SPS beams. An experiment at the SPS-HiRadMat facility (High-Radiation to Materials) using the 440 GeV beam with 144 bunches was performed in July 2012. In this paper we compare the results of this experiment with our calculations of hydrodynamic tunnelling.
	Slides MOODB103 [40.426 MB]

MOPWO039	Experience with High-intensity Beam Scraping and Tail Populations at the Large Hadon Collider	978
	S. Redaelli, R. Bruce, F. Burkart, D. Mirarchi, B. Salvachua, G. Valentino, D. Wollmann CERN, Geneva, Switzerland R.W. Aßmann DESY, Hamburg, Germany G. Valentino University of Malta, Information and Communication Technology, Msida, Malta
	The population of beam tails at the LHC is source of concern because even small fractions of the total beam intensity could represent a potential danger is case of slow or fast losses, e.g. caused by orbit transients or by collimator movements. Different studies have been performed using the technique of collimator scans to probe the beam tail population, for different beam energies and beam intensities. The experience accumulated during the operation at 3.5 TeV and 4 TeV is reviewed and extrapolations to higher energies are considered.

MOPWO049	Lifetime Analysis at High Intensity Colliders Applied to the LHC	1005
	B. Salvachua, R.W. Aßmann, R. Bruce, F. Burkart, S. Redaelli, G. Valentino, D. Wollmann CERN, Geneva, Switzerland G. Valentino University of Malta, Information and Communication Technology, Msida, Malta
	The beam lifetime is one of the main parameters to define the performance of a collider. In a super-conducting machine like the LHC, the lifetime determines the intensity reach for a given collimation cleaning. The beam lifetime can be calculated from the direct measurement of beam current. However, due to the noise in the beam current signal only an average lifetime over several seconds can be calculated. We propose here an alternative method, which uses the signal of the beam loss monitors in the vicinity of the primary collimators to get the instantaneous beam lifetime at the collimators. In this paper we compare the lifetime from the two methods and investigate the minimum lifetime over the LHC cycle for all the physics fills in 2011 and 2012. These data provide a reference for estimates of performance reach from collimator cleaning.

THPEA047	Diamond Particle Detector Properties during High Fluence Material Damage Tests and their Future Applications for Machine Protection in the LHC	3249
	F. Burkart, J. Blanco, J. Borburgh, B. Dehning, M. Di Castro, E. Griesmayer, A. Lechner, J. Lendaro, F. Loprete, R. Losito, S. Montesano, R. Schmidt, D. Wollmann, M. Zerlauth CERN, Geneva, Switzerland E. Griesmayer CIVIDEC Instrumentation, Wien, Austria
	Experience with LHC machine protection (MP) during the last three years of operation shows that the MP systems sufficiently protect the LHC against damage in case of failures leading to beam losses with a time constant exceeding 1ms. An unexpected fast beam loss mechanism, called UFOs, was observed, which could potentially quench superconducting magnets. For such fast losses, but also for better understanding of slower losses, an improved understanding of the loss distribution within a bunch train is required. Diamond particle detectors with bunch-by-bunch resolution and high dynamic range have been developed and successfully tested in the LHC and in experiments to quantify the damage limits of LHC components. This paper will focus on experience gained in use of diamond detectors. The properties of these detectors were measured during high-fluence material damage tests in CERN's HiRadMat facility. The results will be discussed and compared to the cross-calibration with FLUKA simulations. Future applications of these detectors in the LHC to understand beam losses and to improve the protection against fast particle losses will be discussed.

THPFI059	Robustness Test of a Silicon Strip Crystal for Crystal-assisted Collimation Studies in the LHC	3427
	A. Lechner, J. Blanco Sancho, F. Burkart, M. Calviani, M. Di Castro, Y. Gavrikov, J. Lendaro, F. Loprete, R. Losito, C. Maglioni, A. Masi, S. Montesano, A. Perillo-Marcone, P.S. Roguet, W. Scandale, D. Wollmann CERN, Geneva, Switzerland J. Blanco Sancho EPFL, Lausanne, Switzerland F. Burkart IAP, Frankfurt am Main, Germany Y. Gavrikov PNPI, Gatchina, Leningrad District, Russia V. Guidi, A. Mazzolari INFN-Ferrara, Ferrara, Italy V. Guidi, A. Mazzolari UNIFE, Ferrara, Italy W. Scandale LAL, Orsay, France
	Over the past years, the UA9 experiment has successfully demonstrated the viability of enhancing the collimation efficiency of proton and ion beams in the SPS by means of bent crystals. An extension of UA9 to the LHC has been recently approved. The conditions imposed by the LHC operational environment, in particular the tremendous energy density of the beam, require a reliable understanding of the crystal integrity in view of potential accident scenarios such as an asynchronous beam dump. For this purpose, irradiation tests have been performed at the CERN-HiRadMat facility to examine the mechanical strength of a silicon strip crystal in case of direct beam impact. The tests were carried out using a 440 GeV proton beam of 0.5 mm transverse size. The crystal, 3 mm long in beam direction, was exposed to a total of 210¹⁴ protons, with individual pulse intensities reaching up to 310¹³. First visual inspections reveal no macroscopic damage to the crystal. Complementary post-irradiation tests are foreseen to assess microscopic lattice damage as well as the degradation of the channelling efficiency. On behalf of the UA9 Collaboration.

THPFI059	Robustness Test of a Silicon Strip Crystal for Crystal-assisted Collimation Studies in the LHC	3427
	A. Lechner, J. Blanco Sancho, F. Burkart, M. Calviani, M. Di Castro, Y. Gavrikov, J. Lendaro, F. Loprete, R. Losito, C. Maglioni, A. Masi, S. Montesano, A. Perillo-Marcone, P.S. Roguet, W. Scandale, D. Wollmann CERN, Geneva, Switzerland J. Blanco Sancho EPFL, Lausanne, Switzerland F. Burkart IAP, Frankfurt am Main, Germany Y. Gavrikov PNPI, Gatchina, Leningrad District, Russia V. Guidi, A. Mazzolari INFN-Ferrara, Ferrara, Italy V. Guidi, A. Mazzolari UNIFE, Ferrara, Italy W. Scandale LAL, Orsay, France
	Over the past years, the UA9 experiment has successfully demonstrated the viability of enhancing the collimation efficiency of proton and ion beams in the SPS by means of bent crystals. An extension of UA9 to the LHC has been recently approved. The conditions imposed by the LHC operational environment, in particular the tremendous energy density of the beam, require a reliable understanding of the crystal integrity in view of potential accident scenarios such as an asynchronous beam dump. For this purpose, irradiation tests have been performed at the CERN-HiRadMat facility to examine the mechanical strength of a silicon strip crystal in case of direct beam impact. The tests were carried out using a 440 GeV proton beam of 0.5 mm transverse size. The crystal, 3 mm long in beam direction, was exposed to a total of 210¹⁴ protons, with individual pulse intensities reaching up to 310¹³. First visual inspections reveal no macroscopic damage to the crystal. Complementary post-irradiation tests are foreseen to assess microscopic lattice damage as well as the degradation of the channelling efficiency. On behalf of the UA9 Collaboration.