HB2012 - List of Keywords (betatron)

Paper	Title	Other Keywords	Page
MOP215	The Study on Measuring Beta Functions and Phase Advances in the CSNS/RCS	space-charge, kicker, synchrotron, lattice	85
	Y.W. An, S. Wang IHEP, Beijing, People's Republic of China
	As a key component of the China Spallation Neutron Source (CSNS) Project, the Rapid Cycling Synchrotron (RCS) will accumulate and accelerate the proton beams from 80 MeV to 1.6 GeV for extracting and striking the target with a repletion rate of 25 Hz. To check linear optics and locate the quadruple errors, beta function plays an important role in beam diagnostics of a particle accelerate system. The Independent Component Analysis (ICA) is a robust beam diagnosis method by decomposing the samples recorded by turn by turn BPMs (beam position monitors) into the independent components which represent the inherent motion of the beam. The beta functions and phase advances can be derived from the corresponding independent components. Because the linear part of the space charge gives a defocusing effect to the beam, beta function variation will be induced. We find that the ICA method can measure beta functions with a reasonable tolerance under the conditions of strong space charge effects.

MOP246	A Tool Based on the BPM-interpolated Orbit for Speeding up LHC Collimator Alignment	alignment, insertion, GUI, collider	162
	G. Valentino, N.J. Sammut University of Malta, Information and Communication Technology, Msida, Malta R.W. Aßmann, R. Bruce, G.J. Müller, S. Redaelli, B. Salvachua CERN, Geneva, Switzerland
	Beam-based alignment of the LHC collimators is required in order to measure the orbit center and beam size at the collimator locations. During an alignment campaign in March 2012, 80 collimators were aligned at injection energy (450 GeV) using automatic alignment algorithms in 7.5 hours, the fastest setup time achieved since the start of LHC operation in 2008. Reducing the alignment time even further would allow for more frequent alignments, providing more time for physics operation. The proposed tool makes use of the BPM-interpolated orbit to obtain an estimation of the beam centers at the collimators, which can be exploited to quickly move the collimator jaws from the initial parking positions to tighter settings before beam-based alignment commences.

WEO1B04	On Scaling Properties of Third-order Resonance Crossing in Particle Accelerators	resonance, emittance, simulation, booster	394
	S.-Y. Lee Indiana University, Bloomington, Indiana, USA K.Y. Ng Fermilab, Batavia, USA
	Funding: Work supported by the US DOE under contract DEFG02-92ER40747, DE-AC02-07CH11359, and the NSF under contract PHY-0852368 with NSF. The effects of resonances on high power hadron accelerators are explored. These resonances include systematic space-charge resonances, third-order resonance, and other weak random resonances that are often present in FFAG and other RCS accelerators. The distortion of invariant torus during resonance crossing is used to set limit on emittance growth or fraction of particle trapped. The critical resonance strength in the ring lattice is determined from a simple scaling law derived as a function of the tune-ramp rate and initial emittance. Such scaling law can be useful in the evaluation of the performance in high power accelerators.
	Slides WEO1B04 [1.074 MB]

THO1B03	Measurement of Optics Errors and Space Charge Effects	space-charge, optics, coupling, sextupole	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

MOP215

The Study on Measuring Beta Functions and Phase Advances in the CSNS/RCS

space-charge, kicker, synchrotron, lattice

85

Y.W. An, S. Wang
IHEP, Beijing, People's Republic of China

As a key component of the China Spallation Neutron Source (CSNS) Project, the Rapid Cycling Synchrotron (RCS) will accumulate and accelerate the proton beams from 80 MeV to 1.6 GeV for extracting and striking the target with a repletion rate of 25 Hz. To check linear optics and locate the quadruple errors, beta function plays an important role in beam diagnostics of a particle accelerate system. The Independent Component Analysis (ICA) is a robust beam diagnosis method by decomposing the samples recorded by turn by turn BPMs (beam position monitors) into the independent components which represent the inherent motion of the beam. The beta functions and phase advances can be derived from the corresponding independent components. Because the linear part of the space charge gives a defocusing effect to the beam, beta function variation will be induced. We find that the ICA method can measure beta functions with a reasonable tolerance under the conditions of strong space charge effects.

MOP246

A Tool Based on the BPM-interpolated Orbit for Speeding up LHC Collimator Alignment

alignment, insertion, GUI, collider

162

G. Valentino, N.J. Sammut
University of Malta, Information and Communication Technology, Msida, Malta
R.W. Aßmann, R. Bruce, G.J. Müller, S. Redaelli, B. Salvachua
CERN, Geneva, Switzerland

Beam-based alignment of the LHC collimators is required in order to measure the orbit center and beam size at the collimator locations. During an alignment campaign in March 2012, 80 collimators were aligned at injection energy (450 GeV) using automatic alignment algorithms in 7.5 hours, the fastest setup time achieved since the start of LHC operation in 2008. Reducing the alignment time even further would allow for more frequent alignments, providing more time for physics operation. The proposed tool makes use of the BPM-interpolated orbit to obtain an estimation of the beam centers at the collimators, which can be exploited to quickly move the collimator jaws from the initial parking positions to tighter settings before beam-based alignment commences.

WEO1B04

On Scaling Properties of Third-order Resonance Crossing in Particle Accelerators

resonance, emittance, simulation, booster

394

S.-Y. Lee
Indiana University, Bloomington, Indiana, USA
K.Y. Ng
Fermilab, Batavia, USA

Funding: Work supported by the US DOE under contract DEFG02-92ER40747, DE-AC02-07CH11359, and the NSF under contract PHY-0852368 with NSF.
The effects of resonances on high power hadron accelerators are explored. These resonances include systematic space-charge resonances, third-order resonance, and other weak random resonances that are often present in FFAG and other RCS accelerators. The distortion of invariant torus during resonance crossing is used to set limit on emittance growth or fraction of particle trapped. The critical resonance strength in the ring lattice is determined from a simple scaling law derived as a function of the tune-ramp rate and initial emittance. Such scaling law can be useful in the evaluation of the performance in high power accelerators.

Slides WEO1B04 [1.074 MB]

THO1B03

Measurement of Optics Errors and Space Charge Effects

space-charge, optics, coupling, sextupole

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]