IPAC2016 - List of Authors (Thomas, C.A.)

Paper	Title	Page
MOPMR021	Lifetime and Operational Criteria of Proton Beam Instrumentation in the ESS Target Station	276
	Y. Lee, T.J. Shea, C.A. Thomas ESS, Lund, Sweden
	At the European Spallation Source, a 2 GeV, 5 MW proton beam will be delivered from a superconducting linear accelerator to target at a 4% duty factor, which poses demanding requirements on target station design. To tune the beam delivery system and to protect the target station components, the current density, the halo distribution, and the position of the proton beam shall be measured. To provide this functionality, a suite of beam monitoring devices will be deployed in the target monolith, including a multi-wire grid for the beam profile monitoring, thermo-couple assemblies and secondary emission blades for aperture monitoring, and a beam footprint imaging system consisting of optical components and luminescent coatings. Since these devices are exposed to particles that deposit energy and cause a high rate of radiation damage, it is a significant challenge to ensure full functionality. In this paper, material selection, lifetime estimates and operational criteria for these beam-monitoring devices are presented. A number of particle transport and finite-element simulations are performed for analyses, and an empirical validation plan is presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR021
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MOPMR043	Optical System Design for The ESS Proton Beam and Target Diagnostics	347
	M.G. Ibison, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom E. Adli, H. Gjersdal University of Oslo, Oslo, Norway M.G. Ibison, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom T.J. Shea, C.A. Thomas, N. de la Cour ESS, Lund, Sweden
	Funding: Science and Technology Facilities Council The high power and low emittance of the European Spallation Source (ESS) proton beam require a robust protection strategy for the spallation target and its surroundings. For this, the beam will be imaged on passing through scintillator screens coating both the proton beam window (PBW) on exit from the accelerator, and the entry window to the target (TW). Light from the screens must be transported to remote cameras through a 4m high shielding plug of limited aperture. At the same time, the optical path must not compromise the integrity of the shield against neutrons and interaction products. We present the theory underlying the design of the reflective optics for efficient transmission of high-quality images to provide the desired level of protection to the machine, and describe its implementation in the Zemax software tool, as well as the predicted imaging performance. We also consider how the requirements of environment (thermal and radiation), initial alignment and ongoing maintenance for the optical system will be met. Finally we comment on the applicability of optics of this type for diagnostic systems in similar situations at other neutron sources and elsewhere.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR043
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Lifetime and Operational Criteria of Proton Beam Instrumentation in the ESS Target Station

276

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

At the European Spallation Source, a 2 GeV, 5 MW proton beam will be delivered from a superconducting linear accelerator to target at a 4% duty factor, which poses demanding requirements on target station design. To tune the beam delivery system and to protect the target station components, the current density, the halo distribution, and the position of the proton beam shall be measured. To provide this functionality, a suite of beam monitoring devices will be deployed in the target monolith, including a multi-wire grid for the beam profile monitoring, thermo-couple assemblies and secondary emission blades for aperture monitoring, and a beam footprint imaging system consisting of optical components and luminescent coatings. Since these devices are exposed to particles that deposit energy and cause a high rate of radiation damage, it is a significant challenge to ensure full functionality. In this paper, material selection, lifetime estimates and operational criteria for these beam-monitoring devices are presented. A number of particle transport and finite-element simulations are performed for analyses, and an empirical validation plan is presented.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR021

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMR043

Optical System Design for The ESS Proton Beam and Target Diagnostics

347

M.G. Ibison, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
E. Adli, H. Gjersdal
University of Oslo, Oslo, Norway
M.G. Ibison, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
T.J. Shea, C.A. Thomas, N. de la Cour
ESS, Lund, Sweden

Funding: Science and Technology Facilities Council
The high power and low emittance of the European Spallation Source (ESS) proton beam require a robust protection strategy for the spallation target and its surroundings. For this, the beam will be imaged on passing through scintillator screens coating both the proton beam window (PBW) on exit from the accelerator, and the entry window to the target (TW). Light from the screens must be transported to remote cameras through a 4m high shielding plug of limited aperture. At the same time, the optical path must not compromise the integrity of the shield against neutrons and interaction products. We present the theory underlying the design of the reflective optics for efficient transmission of high-quality images to provide the desired level of protection to the machine, and describe its implementation in the Zemax software tool, as well as the predicted imaging performance. We also consider how the requirements of environment (thermal and radiation), initial alignment and ongoing maintenance for the optical system will be met. Finally we comment on the applicability of optics of this type for diagnostic systems in similar situations at other neutron sources and elsewhere.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR043

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)