HB2012 - List of Keywords (luminosity)

Paper	Title	Other Keywords	Page
MOI1A01	LHC - Challenges in Handling Beams Exceeding 100 MJ	beam-losses, insertion, collimation, injection	1
	R. Schmidt CERN, Geneva, Switzerland
	The Large Hadron Collider (LHC) at CERN operates at 4 TeV with high intensity beams, with bunch intensities exceeding the nominal value by several 10 %. The energy stored in each beams is beyond 130 MJ, less than a factor of three from the nominal value at 7 TeV. With these parameters, operation entered into a regime where various effects due to high intensity bunches are observed (instabilities, beam-beam effects, e-cloud effects). The highly efficient collimation system limits beam losses that threaten to quench superconducting magnets. The correct functioning of the machine protection systems is vital during the different operational phases, where already a small fraction of the stored energy is sufficient to damage accelerator equipment or experiments in case of uncontrolled beam loss. Safe operation in presence of such high intensity proton beams is guaranteed by the interplay of many different systems: beam dumping system, beam interlocks, beam instrumentation, equipment monitoring, collimators and absorbers. The experience gained with the key systems of LHC machine protection and collimation will be discussed.
	Slides MOI1A01 [31.116 MB]

MOP248	Brightness Evolution for LHC Beams during the 2012 Run	emittance, brightness, injection, extraction	170
	M. Kuhn Uni HH, Hamburg, Germany G. Arduini, J.F. Comblin, A. Guerrero, V. Kain, B. Mikulec, F. Roncarolo, M. Sapinski, M. Schaumann, R. Steerenberg CERN, Geneva, Switzerland
	One of the reasons for the remarkable achievements of the LHC is the excellent performance of the LHC injector chain. The evolution of the brightness in the injectors and at LHC collision in 2011 and 2012 is discussed. During certain run periods, the brightness from the beam provided by the injectors was lower than usual. Some of the issues have been identified so far and will be reported. The latest results on emittance blow-up investigations through the 2012 LHC cycle will also be presented and compared to the 2011 data. Possible implications for LHC upgrade scenarios will be mentioned.

MOP250	Colliding High Brightness Beams in the LHC	brightness, emittance, beam-beam-effects, proton	180
	T. Pieloni, X. Buffat, R. Giachino, W. Herr, E. Métral, G. Papotti CERN, Geneva, Switzerland
	The CERN-LHC is a high energy particle collider, where intense proton bunches are brought into collision. In order to achieve optimum performance, the bunches must have a high brightness, leading to strong and significant beam-beam effects. Experimental tests during the first two years of its operation have shown that beams with very high brightness can be collided head-on without detrimental effects on the beam dynamics. Such head-on collisions are therefore not expected to limit the LHC performance. Long range beam-beam interactions dominate the adverse effects on the dynamics but can profit from an increased beam brightness, in particular from small emittances. We summarize the experimental results and compare with the theoretical expectations. This allows to optimize the performance for future operation and a definition of promising upgrade scenarios.

WEO1B03	Circular Modes for Flat Beams in LHC	emittance, optics, space-charge, injection	391
	A.V. Burov Fermilab, Batavia, USA
	Benefits and problems for operation with flat beams are discussed.
	Slides WEO1B03 [0.192 MB]

WEO1C06	Measurement and Simulation of Luminosity Leveling in LHC via Beam Separation	simulation, emittance, beam-beam-effects, target	451
	S. Paret, J. Qiang LBNL, Berkeley, California, USA R. Alemany-Fernandez, R. Calaga, R. Giachino, W. Herr, D. Jacquet, G. Papotti, T. Pieloni, L. Ponce, M. Schaumann CERN, Geneva, Switzerland R. Miyamoto ESS, Lund, Sweden
	Funding: This work supported by the US LHC Accelerator Research Program and the National Energy Research Scientific Computing Center of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. Leveling of the luminosity in LHC by means of separating the beams colliding at an interaction point is examined. An experiment in which the separation of the beams was stepwise increased to up to 2.5 times the beam width is presented. The luminosity at all IPs and emittance of the beams were measured to detect possible side effects of the collision with an offset. Strong-strong simulations that closely follow the experimental setup are discussed and compared with the measurements. Finally, potential alternatives for luminosity leveling are briefly described.
	Slides WEO1C06 [1.031 MB]

THO1B04	Space Charge Effects in the NICA Collider Rings	ion, collider, emittance, electron	522
	O.S. Kozlov, S.A. Kostromin, I.N. Meshkov, A.O. Sidorin, A.V. Smirnov, G.V. Trubnikov JINR, Dubna, Moscow Region, Russia A.V. Eliseev JINR/VBLHEP, Dubna, Moscow region, Russia T. Katayama GSI, Darmstadt, Germany
	Accelerator complex NICA, developed at JINR, will provide an ion-ion (Au⁷⁹⁺) collisions at energies of 1-4.5 GeV/u, as well as experiments on collisions of polarized proton-proton and deuteron-deuteron beams. The calculations of the optical properties of superconducting collider rings have been aimed to create appropriate conditions for the collisions of beams and obtaining the required luminosity parameters in the working range of energies. The collider characteristics and the beam dynamics have been worked out mainly for ion-ion mode of the complex. The main effects limiting luminosity are the space charge dominating at the range of 1-3 GeV/u and the intrabeam scattering dominating for 3-4.5 GeV/u beams. Application of both electron and stochastic cooling methods is essential feature of the project. That allows us to suppress these effects in the corresponding energy ranges.
	Slides THO1B04 [3.938 MB]

FRO1A01	Summary of Working Group A: Beam Dynamics in High-Intensity Circular Machines	simulation, space-charge, ion, resonance	606
	E. Métral CERN, Geneva, Switzerland G. Franchetti GSI, Darmstadt, Germany J.A. Holmes ORNL, Oak Ridge, Tennessee, USA
	In this proceeding we summarize the presentations of the HB2012 Workshop session on 'Beam Dynamics in High-Intensity Circular Machines' as well as the outcome of the discussion session. This working group hosted 29 presentations in dedicated sessions plus 5 presentations in a joint session with the working C.
	Slides FRO1A01 [7.420 MB]

Paper

Title

Other Keywords

Page

MOI1A01

LHC - Challenges in Handling Beams Exceeding 100 MJ

beam-losses, insertion, collimation, injection

1

R. Schmidt
CERN, Geneva, Switzerland

The Large Hadron Collider (LHC) at CERN operates at 4 TeV with high intensity beams, with bunch intensities exceeding the nominal value by several 10 %. The energy stored in each beams is beyond 130 MJ, less than a factor of three from the nominal value at 7 TeV. With these parameters, operation entered into a regime where various effects due to high intensity bunches are observed (instabilities, beam-beam effects, e-cloud effects). The highly efficient collimation system limits beam losses that threaten to quench superconducting magnets. The correct functioning of the machine protection systems is vital during the different operational phases, where already a small fraction of the stored energy is sufficient to damage accelerator equipment or experiments in case of uncontrolled beam loss. Safe operation in presence of such high intensity proton beams is guaranteed by the interplay of many different systems: beam dumping system, beam interlocks, beam instrumentation, equipment monitoring, collimators and absorbers. The experience gained with the key systems of LHC machine protection and collimation will be discussed.

Slides MOI1A01 [31.116 MB]

MOP248

Brightness Evolution for LHC Beams during the 2012 Run

emittance, brightness, injection, extraction

170

M. Kuhn
Uni HH, Hamburg, Germany
G. Arduini, J.F. Comblin, A. Guerrero, V. Kain, B. Mikulec, F. Roncarolo, M. Sapinski, M. Schaumann, R. Steerenberg
CERN, Geneva, Switzerland

One of the reasons for the remarkable achievements of the LHC is the excellent performance of the LHC injector chain. The evolution of the brightness in the injectors and at LHC collision in 2011 and 2012 is discussed. During certain run periods, the brightness from the beam provided by the injectors was lower than usual. Some of the issues have been identified so far and will be reported. The latest results on emittance blow-up investigations through the 2012 LHC cycle will also be presented and compared to the 2011 data. Possible implications for LHC upgrade scenarios will be mentioned.

MOP250

Colliding High Brightness Beams in the LHC

brightness, emittance, beam-beam-effects, proton

180

T. Pieloni, X. Buffat, R. Giachino, W. Herr, E. Métral, G. Papotti
CERN, Geneva, Switzerland

The CERN-LHC is a high energy particle collider, where intense proton bunches are brought into collision. In order to achieve optimum performance, the bunches must have a high brightness, leading to strong and significant beam-beam effects. Experimental tests during the first two years of its operation have shown that beams with very high brightness can be collided head-on without detrimental effects on the beam dynamics. Such head-on collisions are therefore not expected to limit the LHC performance. Long range beam-beam interactions dominate the adverse effects on the dynamics but can profit from an increased beam brightness, in particular from small emittances. We summarize the experimental results and compare with the theoretical expectations. This allows to optimize the performance for future operation and a definition of promising upgrade scenarios.

WEO1B03

Circular Modes for Flat Beams in LHC

emittance, optics, space-charge, injection

391

A.V. Burov
Fermilab, Batavia, USA

Benefits and problems for operation with flat beams are discussed.

Slides WEO1B03 [0.192 MB]

WEO1C06

Measurement and Simulation of Luminosity Leveling in LHC via Beam Separation

simulation, emittance, beam-beam-effects, target

451

S. Paret, J. Qiang
LBNL, Berkeley, California, USA
R. Alemany-Fernandez, R. Calaga, R. Giachino, W. Herr, D. Jacquet, G. Papotti, T. Pieloni, L. Ponce, M. Schaumann
CERN, Geneva, Switzerland
R. Miyamoto
ESS, Lund, Sweden

Funding: This work supported by the US LHC Accelerator Research Program and the National Energy Research Scientific Computing Center of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
Leveling of the luminosity in LHC by means of separating the beams colliding at an interaction point is examined. An experiment in which the separation of the beams was stepwise increased to up to 2.5 times the beam width is presented. The luminosity at all IPs and emittance of the beams were measured to detect possible side effects of the collision with an offset. Strong-strong simulations that closely follow the experimental setup are discussed and compared with the measurements. Finally, potential alternatives for luminosity leveling are briefly described.

Slides WEO1C06 [1.031 MB]

THO1B04

Space Charge Effects in the NICA Collider Rings

ion, collider, emittance, electron

522

O.S. Kozlov, S.A. Kostromin, I.N. Meshkov, A.O. Sidorin, A.V. Smirnov, G.V. Trubnikov
JINR, Dubna, Moscow Region, Russia
A.V. Eliseev
JINR/VBLHEP, Dubna, Moscow region, Russia
T. Katayama
GSI, Darmstadt, Germany

Accelerator complex NICA, developed at JINR, will provide an ion-ion (Au⁷⁹⁺) collisions at energies of 1-4.5 GeV/u, as well as experiments on collisions of polarized proton-proton and deuteron-deuteron beams. The calculations of the optical properties of superconducting collider rings have been aimed to create appropriate conditions for the collisions of beams and obtaining the required luminosity parameters in the working range of energies. The collider characteristics and the beam dynamics have been worked out mainly for ion-ion mode of the complex. The main effects limiting luminosity are the space charge dominating at the range of 1-3 GeV/u and the intrabeam scattering dominating for 3-4.5 GeV/u beams. Application of both electron and stochastic cooling methods is essential feature of the project. That allows us to suppress these effects in the corresponding energy ranges.

Slides THO1B04 [3.938 MB]

FRO1A01

Summary of Working Group A: Beam Dynamics in High-Intensity Circular Machines

simulation, space-charge, ion, resonance

606

E. Métral
CERN, Geneva, Switzerland
G. Franchetti
GSI, Darmstadt, Germany
J.A. Holmes
ORNL, Oak Ridge, Tennessee, USA

In this proceeding we summarize the presentations of the HB2012 Workshop session on 'Beam Dynamics in High-Intensity Circular Machines' as well as the outcome of the discussion session. This working group hosted 29 presentations in dedicated sessions plus 5 presentations in a joint session with the working C.

Slides FRO1A01 [7.420 MB]