Difference between revisions of "Sadiq BIW 2012"

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= Abstract =
 
= Abstract =
  
We performed transverse emittance measurement of medical linac at physics department of Idaho State University. Al foil with a thickness of 1 micron used to observe electron via OTR. Imaging system composed of 3 lenses of different focal length were used to improve image quality. We found the projection of electron beam does not follow Gaussian distribution. So, we fit Super-Gaussian distribution to the beam and extracted the transverse emittance.  
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At the Idaho Accelerator Center (IAC), there is a 16 MeV S-band High Repetition Rate Linac (HRRL), which was recently reconfigured its beamline to develop a positron source. The positron source can be generated by sending high quality electron beam to a Tungsten converter. To match optics of the newly configured beamline and to estimate quality of electron beam, we have to measure the transverse emittance of electron beam. In 2011, we developed a beam imaging system with a digital CCD camera, three optical lens, and an OTR screen for the emittance measurement. In this paper, we describe detailed hardware of our beam imaging system and its experimental results.
  
 
= Introduction =
 
= Introduction =

Revision as of 18:16, 10 January 2012

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BIW2012

Abstract Submission to BIW2012

Imaging System for Emittance Measurement of IAC Medical Linac

Abstract

At the Idaho Accelerator Center (IAC), there is a 16 MeV S-band High Repetition Rate Linac (HRRL), which was recently reconfigured its beamline to develop a positron source. The positron source can be generated by sending high quality electron beam to a Tungsten converter. To match optics of the newly configured beamline and to estimate quality of electron beam, we have to measure the transverse emittance of electron beam. In 2011, we developed a beam imaging system with a digital CCD camera, three optical lens, and an OTR screen for the emittance measurement. In this paper, we describe detailed hardware of our beam imaging system and its experimental results.

Introduction

We used 3 lenses to collect OTR light from Al target. To improve image quality, 2 inch diameter lenses were selected. They have focal length of 100 mm, 500 mm and 50 mm, they were called collector lens, fine tune lens and main focus lens respectively. Collector lens has the middle focal length, collects most of the light from the source. Fine tune lens has the biggest focal length, act as fine tune of magnification. Main focus lens: has the smallest focal length, has biggest focusing strength, so act as main focus of light and focuses light to CCD.

Experiment Setup

Camera cage system was located below the OTR target. There are 3 lenses used to focus lights from target to the CCD camera. Target can be pushed into or taken out of the beamline by the actuator at the top.


Fig. HRRL beamline: Optical cage system to focus OTR lights on CCD camera.
Fig. HRRL beamline: Optical lenses lay out for optical cage system.





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