HB2016 - Table of Session: THE4 (Working Group E

Paper

Title

Page

Path to Beam Loss Reduction in the SNS Linac Using Measurements, Simulation and Collimation

548

A.V. Aleksandrov, A.P. Shishlo
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.
The SNS linac operation at its design average power currently is not limited by uncontrolled beam loss. However, further reduction of the beam loss remains an important aspect of the SNS linac tune up and operation. Even small “acceptable” beam loss leads to long term degradation of the accelerator equipment. The current state of model-based tuning at SNS leaves an unacceptably large residual beam loss level and has to be followed by an empirical, sometimes random, adjustment of many parameters to reduce the loss. This talk will discuss a set of coordinated efforts to develop tools for large dynamic range measurements, simulation and collimation in order to facilitate low loss linac tuning.

Slides THAM5Y01 [7.186 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-HB2016-THAM5Y01

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THAM6Y01

Simulations and Detector Technologies for the Beam Loss Monitoring System at the ESS Linac

553

I. Dolenc Kittelmann, T.J. Shea
ESS, Lund, Sweden

The European Spallation Source (ESS), which is currently under construction, will be a neutron source based on 5 MW, 2 GeV superconducting proton linac. Among other beam instrumentation systems, this high intensity linac requires a Beam Loss Monitoring (BLM) system. An important function of the BLM system is to protect the linac from beam-induced damage by detecting unacceptably high beam loss and promptly inhibiting beam production. In addition to protection functionality, the system is expected to provide the means to monitor the beam losses during all modes of operation with the aim to avoid excessive machine activation. This paper focuses on the plans and recent results of the beam loss studies based on Monte Carlo simulations in order to refine the ESS BLM detector requirements by providing the estimations on expected particle fluxes and their spectra at detector locations. Furthermore, the planned detector technologies for the ESS BLM system will be presented.

Slides THAM6Y01 [3.600 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-HB2016-THAM6Y01

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THAM7Y01

Beam-Material Issues for Instrumentation in a 5 MW Monolith

M.A. Hartl, Y. Lee, T.J. Shea, C.A. Thomas
ESS, Lund, Sweden

With the European Spallation Source (ESS) striving to become the world’s most powerful spallation neutron source, the proton accelerator driving the spallation process at ESS has to be very powerful as well. The 5MW/2GeV proton beam delivered from a superconducting linear accelerator sets quite demanding requirements on the beam diagnostic system located in the proton beam instrumentation plug (PBIP). This system is observing beam properties and contains multi-wired grids for beam profile monitoring, thermocouples and secondary emission blades for aperture monitoring and a luminescent coating for imaging the beam spot on the target. These devices are critical for detection of any missteering of the beam and consequently for machine protection. Since the components are exposed to high doses of radiation, radiation damage is to be expected and it is challenging to ensure full functionality of the diagnostic system over a set period of runtime. Material choices for these components in the PBIP with respect to lifetime in a radiation field and operational criteria will be presented.

Slides THAM7Y01 [8.115 MB]

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THAM8Y01

Developments in Non-destructive Beam Profile Monitors

C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: Work supported by EU and STFC.
Non-interceptive beam profile monitors are of great importance for many particle accelerators worldwide. Extra challenges are posed by high energy, high intensity machines and low energy low intensity accelerators. For these applications, existing diagnostics will not be suitable any more due to the high power of the beam or the very small intensities. In addition, many other accelerators ranging from medical to industrial would benefit from the availability of truly non-invasive and real-time beam profile monitors. This contribution presents the different beam monitoring options used at facilities around the world. After a general overview and a discussion of the figures of merit, it focuses on the design details and experimental results of a gas jet-based beam profile monitor at the Cockcroft Institute. It will be shown that this can be operated either as a supersonic gas jet in high vacuum or a residual gas monitor at higher pressures, basing imaging on either atom ionization or light emission.

Slides THAM8Y01 [11.281 MB]

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Paper	Title	Page
THAM5Y01	Path to Beam Loss Reduction in the SNS Linac Using Measurements, Simulation and Collimation	548
	A.V. Aleksandrov, A.P. Shishlo 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. The SNS linac operation at its design average power currently is not limited by uncontrolled beam loss. However, further reduction of the beam loss remains an important aspect of the SNS linac tune up and operation. Even small “acceptable” beam loss leads to long term degradation of the accelerator equipment. The current state of model-based tuning at SNS leaves an unacceptably large residual beam loss level and has to be followed by an empirical, sometimes random, adjustment of many parameters to reduce the loss. This talk will discuss a set of coordinated efforts to develop tools for large dynamic range measurements, simulation and collimation in order to facilitate low loss linac tuning.
	Slides THAM5Y01 [7.186 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-HB2016-THAM5Y01
Export •	reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAM6Y01	Simulations and Detector Technologies for the Beam Loss Monitoring System at the ESS Linac	553
	I. Dolenc Kittelmann, T.J. Shea ESS, Lund, Sweden
	The European Spallation Source (ESS), which is currently under construction, will be a neutron source based on 5 MW, 2 GeV superconducting proton linac. Among other beam instrumentation systems, this high intensity linac requires a Beam Loss Monitoring (BLM) system. An important function of the BLM system is to protect the linac from beam-induced damage by detecting unacceptably high beam loss and promptly inhibiting beam production. In addition to protection functionality, the system is expected to provide the means to monitor the beam losses during all modes of operation with the aim to avoid excessive machine activation. This paper focuses on the plans and recent results of the beam loss studies based on Monte Carlo simulations in order to refine the ESS BLM detector requirements by providing the estimations on expected particle fluxes and their spectra at detector locations. Furthermore, the planned detector technologies for the ESS BLM system will be presented.
	Slides THAM6Y01 [3.600 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-HB2016-THAM6Y01
Export •	reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAM7Y01	Beam-Material Issues for Instrumentation in a 5 MW Monolith
	M.A. Hartl, Y. Lee, T.J. Shea, C.A. Thomas ESS, Lund, Sweden
	With the European Spallation Source (ESS) striving to become the world’s most powerful spallation neutron source, the proton accelerator driving the spallation process at ESS has to be very powerful as well. The 5MW/2GeV proton beam delivered from a superconducting linear accelerator sets quite demanding requirements on the beam diagnostic system located in the proton beam instrumentation plug (PBIP). This system is observing beam properties and contains multi-wired grids for beam profile monitoring, thermocouples and secondary emission blades for aperture monitoring and a luminescent coating for imaging the beam spot on the target. These devices are critical for detection of any missteering of the beam and consequently for machine protection. Since the components are exposed to high doses of radiation, radiation damage is to be expected and it is challenging to ensure full functionality of the diagnostic system over a set period of runtime. Material choices for these components in the PBIP with respect to lifetime in a radiation field and operational criteria will be presented.
	Slides THAM7Y01 [8.115 MB]
Export •	reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAM8Y01	Developments in Non-destructive Beam Profile Monitors
	C.P. Welsch The University of Liverpool, Liverpool, United Kingdom C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: Work supported by EU and STFC. Non-interceptive beam profile monitors are of great importance for many particle accelerators worldwide. Extra challenges are posed by high energy, high intensity machines and low energy low intensity accelerators. For these applications, existing diagnostics will not be suitable any more due to the high power of the beam or the very small intensities. In addition, many other accelerators ranging from medical to industrial would benefit from the availability of truly non-invasive and real-time beam profile monitors. This contribution presents the different beam monitoring options used at facilities around the world. After a general overview and a discussion of the figures of merit, it focuses on the design details and experimental results of a gas jet-based beam profile monitor at the Cockcroft Institute. It will be shown that this can be operated either as a supersonic gas jet in high vacuum or a residual gas monitor at higher pressures, basing imaging on either atom ionization or light emission.
	Slides THAM8Y01 [11.281 MB]
Export •	reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)