BIW2012 - List of Authors (Rehm, G.)

Paper	Title	Page
TUAP01	An X-Ray Pinhole Camera with a Range of Defined Apertures	116
	C.A. Thomas, G. Rehm Diamond, Oxfordshire, United Kingdom R. Bartolini JAI, Oxford, United Kingdom
	Operation of 3rd generation synchrotron light sources is heading towards low emittance coupling offering small vertical beam size and extending the transverse coherence of the X-ray photon beam. In the case of Diamond, exploring operation at 0.1% coupling will imply measuring vertical beam sizes of the order of 7μm (in bending magnets). Measurement of the vertical beam size and coupling with the best accuracy requires a precise knowledge of the Point Spread Function of the electron beam imaging system. At Diamond two X-ray pinhole cameras are used for this measurement. In this paper we present our first results of beam size measurement using a convolution technique, which consists of modelling the image of the source by convolving the pinhole and X-ray camera PSF with a 2-D Gaussian distribution in order to achieve the best possible fit to the measured image. We verify the validity of the method with a series of measurements of the electron beam size with a series of pinholes with well defined apertures varying from 5 to 100μm laser machined into a 200μm Tungsten plate. In this paper we discuss the experimental results and the accuracy of the method.

Paper

Title

Page

An X-Ray Pinhole Camera with a Range of Defined Apertures

116

C.A. Thomas, G. Rehm
Diamond, Oxfordshire, United Kingdom
R. Bartolini
JAI, Oxford, United Kingdom

Operation of 3rd generation synchrotron light sources is heading towards low emittance coupling offering small vertical beam size and extending the transverse coherence of the X-ray photon beam. In the case of Diamond, exploring operation at 0.1% coupling will imply measuring vertical beam sizes of the order of 7μm (in bending magnets). Measurement of the vertical beam size and coupling with the best accuracy requires a precise knowledge of the Point Spread Function of the electron beam imaging system. At Diamond two X-ray pinhole cameras are used for this measurement. In this paper we present our first results of beam size measurement using a convolution technique, which consists of modelling the image of the source by convolving the pinhole and X-ray camera PSF with a 2-D Gaussian distribution in order to achieve the best possible fit to the measured image. We verify the validity of the method with a series of measurements of the electron beam size with a series of pinholes with well defined apertures varying from 5 to 100μm laser machined into a 200μm Tungsten plate. In this paper we discuss the experimental results and the accuracy of the method.