PAC2013 - List of Authors (Aslaninejad, M.)

Paper	Title	Page
MOPMA05	Thermal Design of the FETS Chopper Beam Dump	303
	P. Savage, M. Aslaninejad, P.A. Posocco, J.K. Pozimski Imperial College of Science and Technology, Department of Physics, London, United Kingdom A.P. Letchford, J.K. Pozimski STFC/RAL, Chilton, Didcot, Oxon, United Kingdom S. Mishra Imperial College of Science and Technology, London, United Kingdom
	Funding: M. Shruti was supported by STFC/RAL. The Front End Test Stand Project (FETS) at RAL is being built to demonstrate fast beam chopping. This is required to create precisely defined gaps in the bunched H⁻ beam which is essential in order to minimise beam losses in a synchrotron during injection. The gaps are created in the Medium Energy Beam Transport (MEBT) section of the FETS beam-line using a ‘fast-slow’ chopping scheme. This scheme uses two choppers, one fast and one slow, each kicks a portion of beam into its corresponding downstream beam dump. The challenge for the beam dump design is that it must occupy a limited longitudinal space to ensure that the beam transport is preserved and must absorb a beam power that is close to the sustainable stress limit of common engineering materials. This paper will describe the simulations made to study the cooling scheme required to absorb the power deposited in the dump plates for the fast and slow choppers.

THPSM10	Analysis of Propagated Effects in Proton Depth-Dose Distribution Curves Due To Initial Beam Energy Spread	1403
	P.A. Posocco, M. Aslaninejad, J.F. Piech, S. Zalel Imperial College of Science and Technology, Department of Physics, London, United Kingdom
	Funding: S. Zalel was supported by the Anglo Israel Association. Proton therapy treatment planning uses depth-dose distribution curves of single initial beam energies to create Spread spread Out Bragg Peaks (SOBP). These are used to target specific regions in the body. However, the initial energy spread of the beams leads to an uncertainty in beam energy, affecting the dose distribution. In this paper, previous work (M. Aslaninejad et al., 2011: 189–196) on the depth-dose distribution of proton beams using inelastic-collision cross sections of liquid water is extended into use with chromatic beams. The effect of the initial energy spread on depth-dose distribution curves, the distal dose and the SOBP are discussed. Limits on beam energy spread are suggested.

THPSM11	A Novel Solution for FFAG Proton Gantries	1406
	J. Pasternak, M. Aslaninejad, P.R.N. Holland, P.A. Posocco, G.W. Walton Imperial College of Science and Technology, Department of Physics, London, United Kingdom
	In the recent years FFAG gantries have been studied for medical applications, but none has so far been realised. The FFAG solution would reduce the complexity of beam line set-up, its weight and therefore the cost of the rotating support, in particular for heavy ions. The Imperial College London is using the experience gained in the Pamela Project and in the design and commissioning of EMMA to work on a solution of a non-scaling FFAG gantry, which fulfills the full requirements for the spot scanning - parallel beam treatment technique, and provides an easy interface to the upstream accelerator. The preliminary results will be presented in this paper.

THPSM12	A Ready-to-use Application of Laser-Plasma Accelerators using Gabor Lenses	1409
	J.K. Pozimski, M. Aslaninejad, N. Dover, Z. Najmudin, R.M. Nichols, P.A. Posocco Imperial College of Science and Technology, Department of Physics, London, United Kingdom
	Funding: R.M. Nichols was supported by EPSRC. A realistic particle distribution for a proton beam generated by laser-plasma interaction is required in order to simulate its transport through a Gabor lens system intended for use in radiobiology experiments. A stack of radiochromic films were exposed to a laser-driven proton beam of 25 MeV at the Vulcan Petawatt Experiment at Rutherford Lab and subsequently analysed to find the energy deposited per film and therefore the energy spectrum of the beam. Combined with the information on the radial profile of the dose in the films, it was possible to generate an idealised particle distribution. This distribution was sampled and used as a realistic proton source in a simulation through the Gabor lens system published at IPAC’13, scaled down to 4 MeV to fit the radiobiology experiment requirements.

Paper

Title

Page

Thermal Design of the FETS Chopper Beam Dump

303

P. Savage, M. Aslaninejad, P.A. Posocco, J.K. Pozimski
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
A.P. Letchford, J.K. Pozimski
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
S. Mishra
Imperial College of Science and Technology, London, United Kingdom

Funding: M. Shruti was supported by STFC/RAL.
The Front End Test Stand Project (FETS) at RAL is being built to demonstrate fast beam chopping. This is required to create precisely defined gaps in the bunched H⁻ beam which is essential in order to minimise beam losses in a synchrotron during injection. The gaps are created in the Medium Energy Beam Transport (MEBT) section of the FETS beam-line using a ‘fast-slow’ chopping scheme. This scheme uses two choppers, one fast and one slow, each kicks a portion of beam into its corresponding downstream beam dump. The challenge for the beam dump design is that it must occupy a limited longitudinal space to ensure that the beam transport is preserved and must absorb a beam power that is close to the sustainable stress limit of common engineering materials. This paper will describe the simulations made to study the cooling scheme required to absorb the power deposited in the dump plates for the fast and slow choppers.

THPSM10

Analysis of Propagated Effects in Proton Depth-Dose Distribution Curves Due To Initial Beam Energy Spread

1403

P.A. Posocco, M. Aslaninejad, J.F. Piech, S. Zalel
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

Funding: S. Zalel was supported by the Anglo Israel Association.
Proton therapy treatment planning uses depth-dose distribution curves of single initial beam energies to create Spread spread Out Bragg Peaks (SOBP). These are used to target specific regions in the body. However, the initial energy spread of the beams leads to an uncertainty in beam energy, affecting the dose distribution. In this paper, previous work (M. Aslaninejad et al., 2011: 189–196) on the depth-dose distribution of proton beams using inelastic-collision cross sections of liquid water is extended into use with chromatic beams. The effect of the initial energy spread on depth-dose distribution curves, the distal dose and the SOBP are discussed. Limits on beam energy spread are suggested.

THPSM11

A Novel Solution for FFAG Proton Gantries

1406

J. Pasternak, M. Aslaninejad, P.R.N. Holland, P.A. Posocco, G.W. Walton
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

In the recent years FFAG gantries have been studied for medical applications, but none has so far been realised. The FFAG solution would reduce the complexity of beam line set-up, its weight and therefore the cost of the rotating support, in particular for heavy ions. The Imperial College London is using the experience gained in the Pamela Project and in the design and commissioning of EMMA to work on a solution of a non-scaling FFAG gantry, which fulfills the full requirements for the spot scanning - parallel beam treatment technique, and provides an easy interface to the upstream accelerator. The preliminary results will be presented in this paper.

THPSM12

A Ready-to-use Application of Laser-Plasma Accelerators using Gabor Lenses

1409

J.K. Pozimski, M. Aslaninejad, N. Dover, Z. Najmudin, R.M. Nichols, P.A. Posocco
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

Funding: R.M. Nichols was supported by EPSRC.
A realistic particle distribution for a proton beam generated by laser-plasma interaction is required in order to simulate its transport through a Gabor lens system intended for use in radiobiology experiments. A stack of radiochromic films were exposed to a laser-driven proton beam of 25 MeV at the Vulcan Petawatt Experiment at Rutherford Lab and subsequently analysed to find the energy deposited per film and therefore the energy spectrum of the beam. Combined with the information on the radial profile of the dose in the films, it was possible to generate an idealised particle distribution. This distribution was sampled and used as a realistic proton source in a simulation through the Gabor lens system published at IPAC’13, scaled down to 4 MeV to fit the radiobiology experiment requirements.