IBIC2012 - List of Authors (Rehm, G.)

Paper	Title	Page
MOPA13	Real-time Calculation of Scale Factors of X-ray Beam Position Monitors during User Operation	79
	C. Bloomer, G. Rehm Diamond, Oxfordshire, United Kingdom
	Photoemission based X-ray Beam Position Monitors (XBPMs) are widely used at 3rd generation light sources to both monitor and stabilise the photon beam to sub-micron precision. Traditionally, finding the geometric scale factors requires either systematic stepper motor movements of the XBPM or well controlled electron beam displacements to measure the response of the XBPM. For each Insertion Device gap it is required to repeat this in order to build up a complete set of scale factors covering all possible operating conditions. Elliptically Polarising Undulators further complicate matters by having multiple operating modes which would require multi dimensional lookup tables. Presented in this paper is a method for retrieving the geometric scale factors of an XBPM in real time by making use of the intrinsic small random movements of the electron beam and finding the correlation in synchronous measurements from Electron BPMs and XBPMs at kHz sample rates.

TUPA42	Diagnostics Beamline Optimisation and Image Processing for Sub-ps Streak Camera Bunch Length Measurement	445
	C.A. Thomas, I.P.S. Martin, G. Rehm Diamond, Oxfordshire, United Kingdom
	Low alpha beam lattice at Diamond can generate bunch length as small as 0.6ps. In order to be able to measure reliably such a short bunch, we have been optimising the optical design of the visible Diagnostics beamline, and we have implemented image processing, taking into account the point spread function of the streak camera. The beamline optical design has removed a large chirp of 15ps/150nm bandwidth to 2ps /200nmbandwidth. It has also permit the transport of almost all the available power, increasing the power by a factor 20, yet maintaining the possibility to focus the beam down to less than 20um into the streak camera for the best static streak camera point spread function. The deconvolution technique implemented extends the performance of the streak camera to bunch length measurement much smaller than the 1ps PSF of the streak camera. In this paper we present these two essential features required to measure sub-ps bunched with a streak camera.

Paper

Title

Page

Real-time Calculation of Scale Factors of X-ray Beam Position Monitors during User Operation

79

C. Bloomer, G. Rehm
Diamond, Oxfordshire, United Kingdom

Photoemission based X-ray Beam Position Monitors (XBPMs) are widely used at 3rd generation light sources to both monitor and stabilise the photon beam to sub-micron precision. Traditionally, finding the geometric scale factors requires either systematic stepper motor movements of the XBPM or well controlled electron beam displacements to measure the response of the XBPM. For each Insertion Device gap it is required to repeat this in order to build up a complete set of scale factors covering all possible operating conditions. Elliptically Polarising Undulators further complicate matters by having multiple operating modes which would require multi dimensional lookup tables. Presented in this paper is a method for retrieving the geometric scale factors of an XBPM in real time by making use of the intrinsic small random movements of the electron beam and finding the correlation in synchronous measurements from Electron BPMs and XBPMs at kHz sample rates.

TUPA42

Diagnostics Beamline Optimisation and Image Processing for Sub-ps Streak Camera Bunch Length Measurement

445

C.A. Thomas, I.P.S. Martin, G. Rehm
Diamond, Oxfordshire, United Kingdom

Low alpha beam lattice at Diamond can generate bunch length as small as 0.6ps. In order to be able to measure reliably such a short bunch, we have been optimising the optical design of the visible Diagnostics beamline, and we have implemented image processing, taking into account the point spread function of the streak camera. The beamline optical design has removed a large chirp of 15ps/150nm bandwidth to 2ps /200nmbandwidth. It has also permit the transport of almost all the available power, increasing the power by a factor 20, yet maintaining the possibility to focus the beam down to less than 20um into the streak camera for the best static streak camera point spread function. The deconvolution technique implemented extends the performance of the streak camera to bunch length measurement much smaller than the 1ps PSF of the streak camera. In this paper we present these two essential features required to measure sub-ps bunched with a streak camera.