IPAC2014 - List of Authors (Thomas, C.A.)

Paper	Title	Page
THPME160	Design, Implementation and Preliminary Test Results of the ESS Beam Current Monitor System	3638
	H. Hassanzadegan, A. Jansson, C.A. Thomas ESS, Lund, Sweden J.L. Crisp FRIB, East Lansing, Michigan, USA U. Legat, K. Strniša Cosylab, Ljubljana, Slovenia M. Werner DESY, Hamburg, Germany
	The Beam Current Monitor system of the ESS linac will be mainly based on AC Current Transformers. The BCM system will be used to monitor the beam current and charge in absolute and differential modes. The differential current measurement is also intended for detecting large and sudden beam losses and acting on the Machine Interlock System (MIS), especially in areas where Beam Loss Monitors cannot be reliably used. A demo BCM based on a Bergoz ACCT and MTCA.4 electronics has been procured and integrated into EPICS. A VHDL code has been developed and successfully tested for the required FPGA signal processing including droop compensation, filtering, DC level correction and interfacing to the MIS. This paper gives an overview of the current status of the BCM system design and implementation as well as some preliminary test results in absolute and differential modes.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME160
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THPME166	System Overview and Current Status of the ESS Beam Position Monitors	3653
	H. Hassanzadegan, A. Jansson, C.A. Thomas ESS, Lund, Sweden D. Lipka, M. Werner DESY, Hamburg, Germany A. Young SLAC, Menlo Park, California, USA
	It is planned to install more than 140 button BPMs along the ESS linac. The BPMs will be used to measure the beam position and phase in all foreseen beam modes and to provide input to the Machine Interlock System. The phase measurement is mainly intended for cavity tuning and Time-Of-Flight energy measurements. A customized BPM detector based on the European XFEL button style has been designed for the cold linac through a collaboration with DESY. Large buttons with diameters up to 40 mm are foreseen to provide enough S/N ratio not only with the nominal beam, but also with a low-current or a de-bunched beam. A demo MTCA.4 system has been procured and successfully integrated into EPICS. Also, a customized Rear Transition Module for down-mixing the BPM signals will be developed with SLAC. Electronics tests with a BPM test bench are currently going on at ESS. BPM installation in the linac is foreseen for 2017 and afterwards.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME166
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THPME167	Development of Non-invasive Transverse Profile Monitors for the ESS Linac	3656
	C. Roose, C. Böhme, I. Dolenc Kittelmann, A. Jansson, C.A. Thomas ESS, Lund, Sweden A. Källberg Stockholm University, Stockholm, Sweden
	The European Spallation Source (ESS) consists of a partly superconducting linac which will deliver a 2 GeV proton beam to a rotating tungsten target. In this way, the ESS will be the world's most powerful neutron source. To measure the proton beams transverse profile at high intensity, the ESS develops two types of non-invasive profile devices. The first monitor is based on luminescence of the residual gas, the second one on ionization of the same gas. The latest developments of these profile monitors will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME167
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THPME168	Proton Beam Imaging Options for the ESS Target	3659
	C.A. Thomas, T.J. Grandsaert, M. Göhran, R. Linander, T.J. Shea ESS, Lund, Sweden
	Conceptual design of an imaging system for the ESS proton beam current density on target is presented. The window separating the linac HV from the 1bar He-filled target station will be used as a source for imaging by means of either OTR or luminescence. The system presents many challenges to be addressed. The window and the primary optics will be exposed to extremely high radiation doses, providing heat cycles and mechanical stresses near the engineering limits, but also may change the surface properties of the window and the optics. The window lifetime expected to be less than 1 year will have to be replace bi-annually, imposing remote handling design for the window but also for part of the optics. In addition, the imaging system should be able to form an image from low to high current beam operations, in order to retrieve beam profile distribution and power density distribution of both static and raster beam, imposing a large numerical aperture (NA), but also to transport the image at more than 15m distance where radiation level is compatible with camera and pc stable operation and human access during commissioning and neutron production.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME168
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THPME089	On the Suitability of Longitudinal Profile Measurements using Smith-Purcell Radiation for Short High Current Proton Beams	3439
	J. Barros, N. Delerue, M. Vieille Grosjean LAL, Orsay, France I. Dolenc Kittelmann ESS, Lund, Sweden C.A. Thomas Lund University, Lund, Sweden
	Funding: Financially supported by the Université Paris-Sud (programme "attractivité") and the French ANR (contract ANR-12-JS05-0003-01). The use of Smith-Purcell radiation to measure electrons longitudinal profiles has been demonstrated at several facilities in the picosecond and sub-picosecond range. There is a strong interest for the development of non intercepting longitudinal profile diagnostics for high current proton beams. We present here results of simulations on the expected yield of longitudinal profile monitors using Smith-Purcell radiation for such proton beams.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME089
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Paper

Title

Page

Design, Implementation and Preliminary Test Results of the ESS Beam Current Monitor System

3638

H. Hassanzadegan, A. Jansson, C.A. Thomas
ESS, Lund, Sweden
J.L. Crisp
FRIB, East Lansing, Michigan, USA
U. Legat, K. Strniša
Cosylab, Ljubljana, Slovenia
M. Werner
DESY, Hamburg, Germany

The Beam Current Monitor system of the ESS linac will be mainly based on AC Current Transformers. The BCM system will be used to monitor the beam current and charge in absolute and differential modes. The differential current measurement is also intended for detecting large and sudden beam losses and acting on the Machine Interlock System (MIS), especially in areas where Beam Loss Monitors cannot be reliably used. A demo BCM based on a Bergoz ACCT and MTCA.4 electronics has been procured and integrated into EPICS. A VHDL code has been developed and successfully tested for the required FPGA signal processing including droop compensation, filtering, DC level correction and interfacing to the MIS. This paper gives an overview of the current status of the BCM system design and implementation as well as some preliminary test results in absolute and differential modes.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME160

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

THPME166

System Overview and Current Status of the ESS Beam Position Monitors

3653

H. Hassanzadegan, A. Jansson, C.A. Thomas
ESS, Lund, Sweden
D. Lipka, M. Werner
DESY, Hamburg, Germany
A. Young
SLAC, Menlo Park, California, USA

It is planned to install more than 140 button BPMs along the ESS linac. The BPMs will be used to measure the beam position and phase in all foreseen beam modes and to provide input to the Machine Interlock System. The phase measurement is mainly intended for cavity tuning and Time-Of-Flight energy measurements. A customized BPM detector based on the European XFEL button style has been designed for the cold linac through a collaboration with DESY. Large buttons with diameters up to 40 mm are foreseen to provide enough S/N ratio not only with the nominal beam, but also with a low-current or a de-bunched beam. A demo MTCA.4 system has been procured and successfully integrated into EPICS. Also, a customized Rear Transition Module for down-mixing the BPM signals will be developed with SLAC. Electronics tests with a BPM test bench are currently going on at ESS. BPM installation in the linac is foreseen for 2017 and afterwards.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME166

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THPME167

Development of Non-invasive Transverse Profile Monitors for the ESS Linac

3656

C. Roose, C. Böhme, I. Dolenc Kittelmann, A. Jansson, C.A. Thomas
ESS, Lund, Sweden
A. Källberg
Stockholm University, Stockholm, Sweden

The European Spallation Source (ESS) consists of a partly superconducting linac which will deliver a 2 GeV proton beam to a rotating tungsten target. In this way, the ESS will be the world's most powerful neutron source. To measure the proton beams transverse profile at high intensity, the ESS develops two types of non-invasive profile devices. The first monitor is based on luminescence of the residual gas, the second one on ionization of the same gas. The latest developments of these profile monitors will be presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME167

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

THPME168

Proton Beam Imaging Options for the ESS Target

3659

C.A. Thomas, T.J. Grandsaert, M. Göhran, R. Linander, T.J. Shea
ESS, Lund, Sweden

Conceptual design of an imaging system for the ESS proton beam current density on target is presented. The window separating the linac HV from the 1bar He-filled target station will be used as a source for imaging by means of either OTR or luminescence. The system presents many challenges to be addressed. The window and the primary optics will be exposed to extremely high radiation doses, providing heat cycles and mechanical stresses near the engineering limits, but also may change the surface properties of the window and the optics. The window lifetime expected to be less than 1 year will have to be replace bi-annually, imposing remote handling design for the window but also for part of the optics. In addition, the imaging system should be able to form an image from low to high current beam operations, in order to retrieve beam profile distribution and power density distribution of both static and raster beam, imposing a large numerical aperture (NA), but also to transport the image at more than 15m distance where radiation level is compatible with camera and pc stable operation and human access during commissioning and neutron production.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME168

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

THPME089

On the Suitability of Longitudinal Profile Measurements using Smith-Purcell Radiation for Short High Current Proton Beams

3439

J. Barros, N. Delerue, M. Vieille Grosjean
LAL, Orsay, France
I. Dolenc Kittelmann
ESS, Lund, Sweden
C.A. Thomas
Lund University, Lund, Sweden

Funding: Financially supported by the Université Paris-Sud (programme "attractivité") and the French ANR (contract ANR-12-JS05-0003-01).
The use of Smith-Purcell radiation to measure electrons longitudinal profiles has been demonstrated at several facilities in the picosecond and sub-picosecond range. There is a strong interest for the development of non intercepting longitudinal profile diagnostics for high current proton beams. We present here results of simulations on the expected yield of longitudinal profile monitors using Smith-Purcell radiation for such proton beams.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME089

Export •

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