insertion

Paper	Title	Other Keywords	Page
MOO3A03	First Vibrating Wire Monitor Measurements of a Hard X-ray Undulator Beam at the Advanced Photon Source	photon, radiation, resonance, vacuum	36
	G. Decker ANL, Argonne, Illinois S. G. Arutunian, M. R. Mailian YerPhI, Yerevan G. Rosenbaum UGA, Athens, Georgia
	The first hard x-ray flux measurements with a vibrating wire monitor (VWM) using the acoustic resonance frequencies of two vertically-offset horizontal stainless steel wires as temperature diagnostics were conducted at APS beamline 19-ID. Due to the high sensitivity of this technique, the studies were performed at extremely low power levels using radiation from a 3.3-cm-period permanent magnet hybrid undulator with a 5-mA electron beam at an energy of 7 GeV. The x-ray beam was filtered by transmission through 7 mm of beryllium placed in the photon beam path, assuring that only hard x-rays were detected. The particle beam was scanned through a range of 400 microradians using an asymmetric closed-orbit angle bump, producing two vertical photon beam profiles. The difference between processed wire signals provides a very sensitive measure of photon beam position. Details of the measurements will be given, along with a discussion of the limitations of the method and possible future research directions.
	Slides
TUPB19	Signal Level Calculation for the PETRA-III Beam Position Monitor System	pick-up, vacuum, controls, insertion-device	105
	G. Kube, M. Werner DESY, Hamburg
	Starting mid 2007 the PETRA accelerator at DESY in Hamburg (Germany) will be converted into a new high brilliance light source. For measurement and control of the PETRA-III closed orbit with a resolution of better than 1 micrometer (rms) it is planned to install about 220 button type beam position monitors (BPMs). To guarantee a good performance of the BPM electronics, the button signals have to meet several criteria in time and frequency domain. Therefore signal levels for the monitor types included for installation have been estimated. The results of these calculations will be presented together with a comparison of monitor signals from accelerators in operation, and the expected position resolution will be discussed for a certain type of BPM electronics.
TUPB26	Characterisation of the Systematic Effects of the Insertion Devices with Photon Beam Position Monitors	photon, polarization, undulator, insertion-device	126
	E. D. van Garderen, M. Böge, J. T.M. Chrin, J. Krempasky, V. Schlott, T. Schmidt, A. Streun PSI, Villigen
	The X-ray photon monitors at Swiss Light Source are used for beam-position stabilisation down to sub-micron level. The beam position changes are mainly induced by changing the insertion device (ID) settings. An ID correction scheme involves both digital beam-position monitors (DBPM) located inside the storage ring and analog photon monitors (XBPM) located inside beamline front-ends. However, a beam-position correction scheme optimised for the electron beam is not automatically optimal for the photon beam. A sub-micron stability of the photon beam by changing the ID-settings is possible only if the XBPM readouts are well characterised for each considered ID-setting. We account for some limitations of the XBPM readouts as well as for examples where a sub-micron stability for all considered ID-settings is achieved.
WEPB04	The VEPP-4M Dynamic Aperture Determination Through the Precise Measurement of the Beam Lifetime	dynamic-aperture, simulation, beam-losses, collider	238
	A. N. Zhuravlev, S. I. Gluhov, V. F. Gurko, A. D. Khilchenko, V. A. Kiselev, A. N. Kvashnin, E. B. Levichev, O. I. Meshkov, P. A. Piminov, V. V. Smaluk, P. V. Zubarev BINP SB RAS, Novosibirsk
	To determine experimentally the particle stable area in the electron-positron collider VEPP-4M we measure the beam life time with high accuracy as a function of moving aperture. The measurement is performed by a photodiode installed in the collider diagnostic beam line. The experimental set up and the measurement results are described. Comparison with the tracking simulation is presented.
WEPC06	Single gain radiation tolerant LHC beam loss acquisition card	radiation, beam-losses, monitoring, survey	319
	E. Effinger, B. Dehning, J. E. Emery, G. Ferioli, C. Zamantzas CERN, Geneva
	The beam loss monitoring system is one of the most critical elements for the protection of the LHC. It must prevent the super conducting magnets from quenches and the machine components from damages, caused by beam losses. Ionization chambers and secondary emission based detectors are used on several locations around the ring. The sensors are producing a signal current, which is related to the losses. This current will be measured by a tunnel card, which acquires, digitizes and transmits the data via an optical link to the surface electronic. The usage of the system, for protection and tuning of the LHC and the scale of the LHC, imposed exceptional specifications of the dynamic range and radiation tolerance. The input dynamic allows measurements between 10pA and 1mA and its protected to high pulse of 1.5kV and its corresponding current. To cover this range, a current to frequency converter in combination with an ADC is used. The integrator output voltage is measured with an ADC to improve the resolution. The radiation tolerance required the adaption of conceptional design and a stringent selection components.