IPAC2011 - Table of Session: MOOCB (Beam Instrumentation and Feedback)

Paper

Title

Page

Study on the Realignment Plan for J-PARC Linac after the Tohoku Earthquake in Japan

44

M. Ikegami
KEK, Ibaraki, Japan
T. Morishita
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

A 9.0-magnitude earthquake struck eastern Japan on March 11, 2011, and it gave rise to damages to the buildings of the J-PARC facilities. In particular, the earthquake caused a deformation of the J-PARC linac tunnel resulting an alignment error of several tens of millimeters in both horizontal and vertical directions. It also caused a change in the relative position between the linac and other facilities of J-PARC complex. To restore the beam operation, we should establish a reasonable realignment plan for J-PARC linac taking various constraints into account and possibly tolerating some residual misalignment. In this paper, we show a study on the realignment plan for J-PARC linac including evaluation of the effect of residual misalignment with particle simulations.

Slides MOOCB01 [2.659 MB]

MOOCB02

Commissioning and Performance of the Beam Monitor System for XFEL/SPring-8 “SACLA”

47

Y. Otake, C. Kondo, H. Maesaka
RIKEN Spring-8 Harima, Hyogo, Japan
H. Ego, S. Matsubara, T. Matsumoto, T. Sakurai, H. Tomizawa, K. Yanagida
JASRI/SPring-8, Hyogo-ken, Japan
S.I. Inoue
SES, Hyogo-pref., Japan

The construction of a beam monitor system for XFEL/SPring 8 “SACLA” was completed. The system was developed to realize a spatial resolution of less than 3 um to align a beam orbit for an undulator section with about 100 m long and a temporal resolution to measure bunch lengths from 1 ns to 30 fs to maintain a constant peak beam current conducting stable SASE lasing. The system principally comprises cavity type beam position monitors (BPM), current monitors (CT), screen monitors (SCM) and bunch length measurement instruments, such as an rf deflector and CSR detectors. Commissioning of SACLA started from March 2011, and the monitors performed sufficient roles to tune beams for the lasing. The achieved over-all performances of the system including DAQ are: the BPM have spatial resolution of 300 nm, the bunch length monitors observe bunch lengths from 1ns in an injector with velocity bunching to less than 30 fs after three-stage bunch compressors. The less than a 3 um spatial resolution of the SCM was also confirmed in practical beam operation. By these fulfilled performances, the stable lasing of SACLA will be achieved. This report describes commissioning, performance of the system.

Slides MOOCB02 [7.516 MB]

MOOCB03

A Novel Method for Quasi-non-interceptive Beam Profile Measurement in a Linac

50

A.V. Aleksandrov
ORNL, Oak Ridge, Tennessee, USA

Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy.
Beam profile diagnostics is an important tool for understanding beam dynamics in accelerators. Non-interceptive diagnostics have many great advantages but often are difficult in implementation. We suggest a method of measuring beam profiles that is not truly non-interceptive, because beam has to be intercepted at some point, preferably in the beginning of the linac. But significant difference from a conventional interceptive measurement is that beam is not intercepted at any of the points of measurement along the linac. One important application is measuring beam profiles within cryostats of a super-conducting linac. The equipment required for implementing this diagnostic is simple: a set of slits in the beginning of the accelerator, and a Beam Position Monitor (BPM) in the point of measurement. Beam profiles can be measured simultaneously at every BPM along the linac. In this paper we will discuss details of the method, its limitations, and effect of non-linearity, coupling and space charge. Results of a demonstration experiment at SNS will be presented and discussed.

Slides MOOCB03 [3.365 MB]

Paper	Title	Page
MOOCB01	Study on the Realignment Plan for J-PARC Linac after the Tohoku Earthquake in Japan	44
	M. Ikegami KEK, Ibaraki, Japan T. Morishita JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	A 9.0-magnitude earthquake struck eastern Japan on March 11, 2011, and it gave rise to damages to the buildings of the J-PARC facilities. In particular, the earthquake caused a deformation of the J-PARC linac tunnel resulting an alignment error of several tens of millimeters in both horizontal and vertical directions. It also caused a change in the relative position between the linac and other facilities of J-PARC complex. To restore the beam operation, we should establish a reasonable realignment plan for J-PARC linac taking various constraints into account and possibly tolerating some residual misalignment. In this paper, we show a study on the realignment plan for J-PARC linac including evaluation of the effect of residual misalignment with particle simulations.
	Slides MOOCB01 [2.659 MB]

MOOCB02	Commissioning and Performance of the Beam Monitor System for XFEL/SPring-8 “SACLA”	47
	Y. Otake, C. Kondo, H. Maesaka RIKEN Spring-8 Harima, Hyogo, Japan H. Ego, S. Matsubara, T. Matsumoto, T. Sakurai, H. Tomizawa, K. Yanagida JASRI/SPring-8, Hyogo-ken, Japan S.I. Inoue SES, Hyogo-pref., Japan
	The construction of a beam monitor system for XFEL/SPring 8 “SACLA” was completed. The system was developed to realize a spatial resolution of less than 3 um to align a beam orbit for an undulator section with about 100 m long and a temporal resolution to measure bunch lengths from 1 ns to 30 fs to maintain a constant peak beam current conducting stable SASE lasing. The system principally comprises cavity type beam position monitors (BPM), current monitors (CT), screen monitors (SCM) and bunch length measurement instruments, such as an rf deflector and CSR detectors. Commissioning of SACLA started from March 2011, and the monitors performed sufficient roles to tune beams for the lasing. The achieved over-all performances of the system including DAQ are: the BPM have spatial resolution of 300 nm, the bunch length monitors observe bunch lengths from 1ns in an injector with velocity bunching to less than 30 fs after three-stage bunch compressors. The less than a 3 um spatial resolution of the SCM was also confirmed in practical beam operation. By these fulfilled performances, the stable lasing of SACLA will be achieved. This report describes commissioning, performance of the system.
	Slides MOOCB02 [7.516 MB]

MOOCB03	A Novel Method for Quasi-non-interceptive Beam Profile Measurement in a Linac	50
	A.V. Aleksandrov ORNL, Oak Ridge, Tennessee, USA
	Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. Beam profile diagnostics is an important tool for understanding beam dynamics in accelerators. Non-interceptive diagnostics have many great advantages but often are difficult in implementation. We suggest a method of measuring beam profiles that is not truly non-interceptive, because beam has to be intercepted at some point, preferably in the beginning of the linac. But significant difference from a conventional interceptive measurement is that beam is not intercepted at any of the points of measurement along the linac. One important application is measuring beam profiles within cryostats of a super-conducting linac. The equipment required for implementing this diagnostic is simple: a set of slits in the beginning of the accelerator, and a Beam Position Monitor (BPM) in the point of measurement. Beam profiles can be measured simultaneously at every BPM along the linac. In this paper we will discuss details of the method, its limitations, and effect of non-linearity, coupling and space charge. Results of a demonstration experiment at SNS will be presented and discussed.
	Slides MOOCB03 [3.365 MB]