IBIC2016 - List of Authors (Pertica, A.)

Paper	Title	Page
TUPG24	Online Total Ionisation Dosimeter (TID) Monitoring Using Semiconductor Based Radiation Sensors in the ISIS Proton Synchrotron	379
	D.M. Harryman, A. Pertica STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	During routine operation, the radiation levels in the ISIS proton synchrotron become high enough to permanently affect systems and electronics. This can potentially cause critical components to fail unexpectedly or denature over time, causing disruption for users of the ISIS facility or a loss of accuracy on a number of systems. To study the long term effects of ionising radiation on ISIS systems and electronics, the total dose received by such components must be recorded. A semiconductor based online Total Ionisation Dosimeter (TID) was developed to do this, using pin diodes and Radiation sensing Field Effect Transistors (RadFETs) to measure the total ionisation dose. Measurements are made by feeding the TIDs with a constant current, with the threshold voltage on each device increasing in relation to the amount of radiation that it has received. This paper will look at preliminary offline results using off the shelf Field Effect Transistors (FETs) and diodes, before discussing the development of the RadFET online monitor and the results it has gathered thus far. Finally the paper will look at future applications and studies that this type of monitor will enable.
	Poster TUPG24 [1.235 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG24
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WEPG59	Thermal Simulations of Wire Profile Monitors in ISIS Extracted Proton Beamline 1	785
	D.W. Posthuma de Boer, A. Pertica STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	Wire scanners and secondary emission (SEM) grids are used for measurements of transverse beam profile at the ISIS neutron and muon source. Silicon carbide-coated carbon fibre wires are used in profile monitors throughout the ISIS accelerator. One such SEM grid is currently installed close to the target in EPB2 and is intercepted by the 800 MeV proton beam at a repetition rate of 10 Hz. Future profile measurements will require another of these monitors to be installed close to the target in EPB1; intercepted with a repetition rate of 40 Hz. Wires intercepting the ion beam are heated due to the deposition of beam-energy. Thermal simulations for the higher repetition rate were performed using ANSYS and a numerical code. The numerical code was then expanded to include various beam, wire and material properties. Assumptions for temperature dependent material emissivities and heat capacities were included in the simulation. Estimated temperatures due to the energy deposited by protons, and approximate values of deposited energy from the expected neutron flux are presented. The effects on wire-temperature of various beam and wire parameters are also discussed.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG59
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WEPG68	An Investigation into the Behaviour of Residual Gas Ionisation Profile Monitors in the ISIS Extracted Beamline	807
	C.C. Wilcox, B. Jones, A. Pertica, R.E. Williamson STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	Non-destructive beam profile measurements at the ISIS neutron source are performed using Multi-Channel Profile Monitors (MCPMs). These use residual gas ionisation within the beam pipe, with the ions being guided to an array of 40 Channeltron electron multipliers by a high voltage drift field. Non-uniform transverse electric fields within these monitors are caused by the drift field and the beam's space charge. Longitudinally, a saddle point located between the drift field plate and the opposing compensating field plate introduces extra complexity into the ion motion. To allow for detailed studies of this behaviour, an MCPM has been placed in Extracted Proton Beamline 1 (EPB1) where the beam is well defined. Simulations of the profiles obtained by this monitor are performed using machine measurements, CST EM Studio and a simple C++ particle tracking code. This paper describes the process used to simulate MCPM profiles along with a comparison of simulated and measured results. Trajectories of detected ions from their creation to the Channeltrons are discussed, together with a study of Channeltron detection characteristics carried out in the ISIS diagnostics laboratory vacuum tank.
	Poster WEPG68 [2.703 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG68
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Online Total Ionisation Dosimeter (TID) Monitoring Using Semiconductor Based Radiation Sensors in the ISIS Proton Synchrotron

379

D.M. Harryman, A. Pertica
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

During routine operation, the radiation levels in the ISIS proton synchrotron become high enough to permanently affect systems and electronics. This can potentially cause critical components to fail unexpectedly or denature over time, causing disruption for users of the ISIS facility or a loss of accuracy on a number of systems. To study the long term effects of ionising radiation on ISIS systems and electronics, the total dose received by such components must be recorded. A semiconductor based online Total Ionisation Dosimeter (TID) was developed to do this, using pin diodes and Radiation sensing Field Effect Transistors (RadFETs) to measure the total ionisation dose. Measurements are made by feeding the TIDs with a constant current, with the threshold voltage on each device increasing in relation to the amount of radiation that it has received. This paper will look at preliminary offline results using off the shelf Field Effect Transistors (FETs) and diodes, before discussing the development of the RadFET online monitor and the results it has gathered thus far. Finally the paper will look at future applications and studies that this type of monitor will enable.

Poster TUPG24 [1.235 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG24

Export •

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

WEPG59

Thermal Simulations of Wire Profile Monitors in ISIS Extracted Proton Beamline 1

785

D.W. Posthuma de Boer, A. Pertica
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

Wire scanners and secondary emission (SEM) grids are used for measurements of transverse beam profile at the ISIS neutron and muon source. Silicon carbide-coated carbon fibre wires are used in profile monitors throughout the ISIS accelerator. One such SEM grid is currently installed close to the target in EPB2 and is intercepted by the 800 MeV proton beam at a repetition rate of 10 Hz. Future profile measurements will require another of these monitors to be installed close to the target in EPB1; intercepted with a repetition rate of 40 Hz. Wires intercepting the ion beam are heated due to the deposition of beam-energy. Thermal simulations for the higher repetition rate were performed using ANSYS and a numerical code. The numerical code was then expanded to include various beam, wire and material properties. Assumptions for temperature dependent material emissivities and heat capacities were included in the simulation. Estimated temperatures due to the energy deposited by protons, and approximate values of deposited energy from the expected neutron flux are presented. The effects on wire-temperature of various beam and wire parameters are also discussed.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG59

Export •

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

WEPG68

An Investigation into the Behaviour of Residual Gas Ionisation Profile Monitors in the ISIS Extracted Beamline

807

C.C. Wilcox, B. Jones, A. Pertica, R.E. Williamson
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

Non-destructive beam profile measurements at the ISIS neutron source are performed using Multi-Channel Profile Monitors (MCPMs). These use residual gas ionisation within the beam pipe, with the ions being guided to an array of 40 Channeltron electron multipliers by a high voltage drift field. Non-uniform transverse electric fields within these monitors are caused by the drift field and the beam's space charge. Longitudinally, a saddle point located between the drift field plate and the opposing compensating field plate introduces extra complexity into the ion motion. To allow for detailed studies of this behaviour, an MCPM has been placed in Extracted Proton Beamline 1 (EPB1) where the beam is well defined. Simulations of the profiles obtained by this monitor are performed using machine measurements, CST EM Studio and a simple C++ particle tracking code. This paper describes the process used to simulate MCPM profiles along with a comparison of simulated and measured results. Trajectories of detected ions from their creation to the Channeltrons are discussed, together with a study of Channeltron detection characteristics carried out in the ISIS diagnostics laboratory vacuum tank.

Poster WEPG68 [2.703 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG68

Export •

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