IBIC2014 - List of Authors (Schmidt-Foehre, F.)

Paper	Title	Page
TUPF08	Design, Development and Commissioning of a MTCA-Based Button and Strip-Line BPM System for FLASH2	320
	B. Lorbeer, N. Baboi, L.P. Petrosyan, F. Schmidt-Föhre DESY, Hamburg, Germany
	The FLASH (Free Electron Laser in Hamburg) facility at DESY (Deutsches Elektronen-Synchrotron) in Germany has been extended by a new undulator line called FLASH2 to provide twice as many experimental stations for users in the future. After the acceleration of the electron bunch train up to 1.2GeV, a part can be kicked into FLASH2, while the other is going to the old undulator line. In order to tune the wavelength of the SASE (Self Amplified Spontaneous Emission), the new line is equipped with variable gap undulators. The commissioning phase of FLASH2 started in early 2014 and is planned to be continued parasitically during user operation in FLASH1. One key point during first beam commissioning is the availability of standard diagnostic devices such as BPM (Beam Position Monitor). In this paper we present the design and first operational experience of a new BPM system for button and strip-line monitors based on MTCA.4. This is referred to as LCBPM (low charge BPM) in contrast to the old systems at FLASH initially designed for bunch charges of 1nC and higher. We summarize the recent analog and digital hardware development progress[,***] and first commissioning experience of this new BPM system at FLASH2 and present a first estimation of its resolution in a large charge range from 1nC down to 100pC and smaller. flash2.desy.de B. Lorbeer et.al.,TUPA19, IBIC2012 * MTCA.4 (Micro Telecommunications Computing Architecture ) for physics **** Frank Schmidt-Foehre et.al.,IPAC2014 Dresden
Export •	reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

TUPF09	Calibration of OLYMPUS/DORIS Beam Position Monitors	324
	U. Schneekloth, N. Görrissen, G. Kube, J. Neugebauer, Ru. Neumann, F. Schmidt-Föhre DESY, Hamburg, Germany
	The goal of the OLYMPUS experiment is a precise measurement of the ratio of the positron-proton and electron-proton elastic scattering cross sections in order to quantify the effect of two-photon exchange. The experiment was performed using intense beams of electrons and positrons stored in the DORIS ring at Deutsches Elektronen Synchrotron in Hamburg, impinging on an un-polarized, internal, hydrogen gas target. An essential ingredient of the experiment is a precise determination of the luminosity, which requires a precise knowledge of the beam position of both beam species. During DORIS operation cylindrical button beam position monitors, read out by two independent electronics systems, were mounted up- and downstream of the target chamber. After the end of operation, the readout systems were cross-calibrated. The BPMs were then calibrated using a test-stand, consisting of a wire scanner assembly. The beam was simulated by applying an RF signal to the wire. This paper describes the calibration principles and test setup, together with the results compared to the expected BPM response.
Export •	reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

Paper

Title

Page

Design, Development and Commissioning of a MTCA-Based Button and Strip-Line BPM System for FLASH2

320

B. Lorbeer, N. Baboi, L.P. Petrosyan, F. Schmidt-Föhre
DESY, Hamburg, Germany

The FLASH (Free Electron Laser in Hamburg) facility at DESY (Deutsches Elektronen-Synchrotron) in Germany has been extended by a new undulator line called FLASH2 to provide twice as many experimental stations for users in the future*. After the acceleration of the electron bunch train up to 1.2GeV, a part can be kicked into FLASH2, while the other is going to the old undulator line. In order to tune the wavelength of the SASE (Self Amplified Spontaneous Emission), the new line is equipped with variable gap undulators. The commissioning phase of FLASH2 started in early 2014 and is planned to be continued parasitically during user operation in FLASH1. One key point during first beam commissioning is the availability of standard diagnostic devices such as BPM (Beam Position Monitor). In this paper we present the design and first operational experience of a new BPM system for button and strip-line monitors based on MTCA.4***. This is referred to as LCBPM (low charge BPM) in contrast to the old systems at FLASH initially designed for bunch charges of 1nC and higher. We summarize the recent analog and digital hardware development progress[**,****] and first commissioning experience of this new BPM system at FLASH2 and present a first estimation of its resolution in a large charge range from 1nC down to 100pC and smaller.
* flash2.desy.de
** B. Lorbeer et.al.,TUPA19, IBIC2012
*** MTCA.4 (Micro Telecommunications Computing Architecture ) for physics
**** Frank Schmidt-Foehre et.al.,IPAC2014 Dresden

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

TUPF09

Calibration of OLYMPUS/DORIS Beam Position Monitors

324

U. Schneekloth, N. Görrissen, G. Kube, J. Neugebauer, Ru. Neumann, F. Schmidt-Föhre
DESY, Hamburg, Germany

The goal of the OLYMPUS experiment is a precise measurement of the ratio of the positron-proton and electron-proton elastic scattering cross sections in order to quantify the effect of two-photon exchange. The experiment was performed using intense beams of electrons and positrons stored in the DORIS ring at Deutsches Elektronen Synchrotron in Hamburg, impinging on an un-polarized, internal, hydrogen gas target. An essential ingredient of the experiment is a precise determination of the luminosity, which requires a precise knowledge of the beam position of both beam species. During DORIS operation cylindrical button beam position monitors, read out by two independent electronics systems, were mounted up- and downstream of the target chamber. After the end of operation, the readout systems were cross-calibrated. The BPMs were then calibrated using a test-stand, consisting of a wire scanner assembly. The beam was simulated by applying an RF signal to the wire. This paper describes the calibration principles and test setup, together with the results compared to the expected BPM response.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)