HB2012 - List of Keywords (optics)

Paper	Title	Other Keywords	Page
MOI1C03	Beam Loss Mechanisms in High Intensity Linacs	linac, DTL, proton, ion	36
	M.A. Plum ORNL, Oak Ridge, Tennessee, USA
	Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725. Beam loss is a critical issue in high intensity linacs, and much work is done during both the design and operation phases to keep the loss down to manageable levels. Linacs for H⁻ ion beams have many more loss mechanisms compared to H⁺ (proton) linacs. Interesting H⁻ beam loss mechanisms include residual gas stripping, H⁺ capture and acceleration, field stripping, and intra-beam stripping (IBSt). Beam halo formation, and ion source or RF turn on/off transients, are examples of beam loss mechanisms that are common for both H⁺ and H⁻ accelerators. The IBSt mechanism has recently been characterized at the Oak Ridge Spallation Neutron Source, and we have found that it accounts for most of the loss in the superconducting linac. In this paper we will detail the IBSt measurements, and also discuss the other beam loss mechanisms that are important for high intensity linacs.
	Slides MOI1C03 [5.588 MB]

TUO3C05	Beam Commissioning Plan for CSNS Accelerators	DTL, linac, injection, target	334
	S. Wang, S. Fu, H.F. Ouyang, J. Peng IHEP, Beijing, People's Republic of China
	Funding: Supported by National Natural Science Foundation of China (11175193) The China Spallation Neutron Source (CSNS) is now under construction, and the beam commissioning of ion source will start from the end of 2013, and will last several years for whole accelerator. The commissioning plan for CSNS accelerators will be presented in the presentation, including the commissioning correlated parameters, the goal at different commissioning stages and some key commissioning procedures for each part of accelerators. The detailed schedule for commissioning will be also given.
	Slides TUO3C05 [3.574 MB]

WEO1B01	Low Gamma Transition Optics for the SPS: Simulation and Experimental Results for High Brightness Beams	emittance, injection, electron, extraction	381
	H. Bartosik, G. Arduini, T. Argyropoulos, T. Bohl, K. Cornelis, J. Esteban Müller, K.S.B. Li, Y. Papaphilippou, G. Rumolo, B. Salvant, F. Schmidt, E.N. Shaposhnikova, H. Timko CERN, Geneva, Switzerland A.Y. Molodozhentsev KEK, Ibaraki, Japan
	The single bunch transverse mode coupling instability (TMCI) at injection is presently one of the main intensity limitation for LHC beams in the SPS. A new optics for the SPS with lower transition energy yields an almost 3-fold increase of the slip factor at injection energy and thus a significantly higher TMCI threshold, as demonstrated both in simulations and in experimental studies. It is observed furthermore that the low gamma transition optics yields better longitudinal stability throughout the entire acceleration cycle. In addition, simulations predict a higher threshold for the electron cloud driven single bunch instability, which might become an important limitation for high intensity LHC beams with the nominal 25 ns bunch spacing. This contribution gives a summary of the experimental and simulation studies, addressing also space charge effects and the achievable brightness with high intensity single bunch beams.

WEO1B02	Optics Design Optimization for IBS Dominated Beams	emittance, scattering, ion, damping	386
	F. Antoniou, H. Bartosik, Y. Papaphilippou CERN, Geneva, Switzerland T. Demma LAL, Orsay, France N. Milas, A. Streun PSI, Villigen PSI, Switzerland M.T.F. Pivi SLAC, Menlo Park, California, USA
	Intra-beam scattering is a small angle multiple Coulomb scattering effect, leading to emittance growth. It becomes important for high brightness beams in low emittance lepton rings, but also hadron synchrotrons and ring colliders. Several theoretical models have been developed over the years, however, when the IBS becomes predominant, the divergence between the models becomes important. In addition, the theoretical models are based on the consideration of Gaussian beams and uncoupled transverse motion. Recently, two multi-particle tracking codes have been developed, in order to enable the understanding of the IBS influence on the beam distribution and the inclusion of coupling. The comparison between theoretical models in different lattices and different regimes is discussed here and the benchmarking of the theoretical models with the tracking codes is presented. Finally, first measurement results are presented in low emittance rings and hadron synchrotrons.
	Slides WEO1B02 [2.389 MB]

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

THO1B02	Test of Optical Stochastic Cooling in Fermilab	damping, radiation, kicker, pick-up	514
	V.A. Lebedev Fermilab, Batavia, USA M.S. Zolotorev LBNL, Berkeley, California, USA
	A new 150 MeV electron storage ring is planned to be build in Fermilab. The construction of new machine pursues two goals a test of highly non-linear integrable optics and a test of optical stochastic cooling (OSC). This paper discusses details of OSC arrangements and choice of major parameters of the cooling scheme. At the first step the cooling will be achieved without optical amplifier. It should introduce the damping rates of about 1 order of magnitudes higher than the cooling rates due to synchrotron radiation. Similar scheme looks as a promising technique for the LHC luminosity upgrade. Its details are also discussed.
	Slides THO1B02 [1.109 MB]

THO1B03	Measurement of Optics Errors and Space Charge Effects	space-charge, coupling, sextupole, betatron	517
	K. Ohmi, Y. Sato, J. Takano KEK, Ibaraki, Japan S. Hatakeyama JAEA/J-PARC, Tokai-mura, Japan
	Beta function and x-y coupling are measured using turn-by-turn monitor system in J-PARC MR. Errors of the optics parameters induce to undesirable resonances due to lattice nonlinear magnets and space charge force. We estimate the resonance strength and the degradation of emittance growth and beam loss.
	Slides THO1B03 [2.240 MB]

Paper

Title

Other Keywords

Page

MOI1C03

Beam Loss Mechanisms in High Intensity Linacs

linac, DTL, proton, ion

36

M.A. Plum
ORNL, Oak Ridge, Tennessee, USA

Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.
Beam loss is a critical issue in high intensity linacs, and much work is done during both the design and operation phases to keep the loss down to manageable levels. Linacs for H⁻ ion beams have many more loss mechanisms compared to H⁺ (proton) linacs. Interesting H⁻ beam loss mechanisms include residual gas stripping, H⁺ capture and acceleration, field stripping, and intra-beam stripping (IBSt). Beam halo formation, and ion source or RF turn on/off transients, are examples of beam loss mechanisms that are common for both H⁺ and H⁻ accelerators. The IBSt mechanism has recently been characterized at the Oak Ridge Spallation Neutron Source, and we have found that it accounts for most of the loss in the superconducting linac. In this paper we will detail the IBSt measurements, and also discuss the other beam loss mechanisms that are important for high intensity linacs.

Slides MOI1C03 [5.588 MB]

TUO3C05

Beam Commissioning Plan for CSNS Accelerators

DTL, linac, injection, target

334

S. Wang, S. Fu, H.F. Ouyang, J. Peng
IHEP, Beijing, People's Republic of China

Funding: Supported by National Natural Science Foundation of China (11175193)
The China Spallation Neutron Source (CSNS) is now under construction, and the beam commissioning of ion source will start from the end of 2013, and will last several years for whole accelerator. The commissioning plan for CSNS accelerators will be presented in the presentation, including the commissioning correlated parameters, the goal at different commissioning stages and some key commissioning procedures for each part of accelerators. The detailed schedule for commissioning will be also given.

Slides TUO3C05 [3.574 MB]

WEO1B01

Low Gamma Transition Optics for the SPS: Simulation and Experimental Results for High Brightness Beams

emittance, injection, electron, extraction

381

H. Bartosik, G. Arduini, T. Argyropoulos, T. Bohl, K. Cornelis, J. Esteban Müller, K.S.B. Li, Y. Papaphilippou, G. Rumolo, B. Salvant, F. Schmidt, E.N. Shaposhnikova, H. Timko
CERN, Geneva, Switzerland
A.Y. Molodozhentsev
KEK, Ibaraki, Japan

The single bunch transverse mode coupling instability (TMCI) at injection is presently one of the main intensity limitation for LHC beams in the SPS. A new optics for the SPS with lower transition energy yields an almost 3-fold increase of the slip factor at injection energy and thus a significantly higher TMCI threshold, as demonstrated both in simulations and in experimental studies. It is observed furthermore that the low gamma transition optics yields better longitudinal stability throughout the entire acceleration cycle. In addition, simulations predict a higher threshold for the electron cloud driven single bunch instability, which might become an important limitation for high intensity LHC beams with the nominal 25 ns bunch spacing. This contribution gives a summary of the experimental and simulation studies, addressing also space charge effects and the achievable brightness with high intensity single bunch beams.

WEO1B02

Optics Design Optimization for IBS Dominated Beams

emittance, scattering, ion, damping

386

F. Antoniou, H. Bartosik, Y. Papaphilippou
CERN, Geneva, Switzerland
T. Demma
LAL, Orsay, France
N. Milas, A. Streun
PSI, Villigen PSI, Switzerland
M.T.F. Pivi
SLAC, Menlo Park, California, USA

Intra-beam scattering is a small angle multiple Coulomb scattering effect, leading to emittance growth. It becomes important for high brightness beams in low emittance lepton rings, but also hadron synchrotrons and ring colliders. Several theoretical models have been developed over the years, however, when the IBS becomes predominant, the divergence between the models becomes important. In addition, the theoretical models are based on the consideration of Gaussian beams and uncoupled transverse motion. Recently, two multi-particle tracking codes have been developed, in order to enable the understanding of the IBS influence on the beam distribution and the inclusion of coupling. The comparison between theoretical models in different lattices and different regimes is discussed here and the benchmarking of the theoretical models with the tracking codes is presented. Finally, first measurement results are presented in low emittance rings and hadron synchrotrons.

Slides WEO1B02 [2.389 MB]

WEO1B03

Circular Modes for Flat Beams in LHC

emittance, space-charge, luminosity, injection

391

A.V. Burov
Fermilab, Batavia, USA

Benefits and problems for operation with flat beams are discussed.

Slides WEO1B03 [0.192 MB]

THO1B02

Test of Optical Stochastic Cooling in Fermilab

damping, radiation, kicker, pick-up

514

V.A. Lebedev
Fermilab, Batavia, USA
M.S. Zolotorev
LBNL, Berkeley, California, USA

A new 150 MeV electron storage ring is planned to be build in Fermilab. The construction of new machine pursues two goals a test of highly non-linear integrable optics and a test of optical stochastic cooling (OSC). This paper discusses details of OSC arrangements and choice of major parameters of the cooling scheme. At the first step the cooling will be achieved without optical amplifier. It should introduce the damping rates of about 1 order of magnitudes higher than the cooling rates due to synchrotron radiation. Similar scheme looks as a promising technique for the LHC luminosity upgrade. Its details are also discussed.

Slides THO1B02 [1.109 MB]

THO1B03

Measurement of Optics Errors and Space Charge Effects

space-charge, coupling, sextupole, betatron

517

K. Ohmi, Y. Sato, J. Takano
KEK, Ibaraki, Japan
S. Hatakeyama
JAEA/J-PARC, Tokai-mura, Japan

Beta function and x-y coupling are measured using turn-by-turn monitor system in J-PARC MR. Errors of the optics parameters induce to undesirable resonances due to lattice nonlinear magnets and space charge force. We estimate the resonance strength and the degradation of emittance growth and beam loss.

Slides THO1B03 [2.240 MB]