| Paper |
Title |
Other Keywords |
Page |
| MOO2A03 |
FERMI@elettra Diagnostics
|
diagnostics, linac |
20 |
| |
- M. Ferianis
ELETTRA, Basovizza, Trieste
| |
FERMI@elettra is the fourth generation light source currently under construction at the Sincrotrone Trieste Laboratory. It is a seeded FEL based on the existing 1.0GeV Linac which will be fitted with FEL specific sub-systems like a new photoinjector and two bunch compressors to obtain in front of the undulator chain a stable and high quality beam. Due to the challeging beam parameters, the diagnostics play a key role for the successfull commissioning first, and then for a reliable operation of the new faciltiy. In this paper we give an overview on the FERMI diagnostics operating in the 6-D phase space along with some keynotes on the timing system which is an integral part of the longitudinal diagnostics.
|
|
|
|
| TUPB25 |
Beam Profile Measurement with Optical Fiber Sensors at FLASH
|
beam-losses, radiation, controls, monitoring |
123 |
| |
- W. Goettmann, F. Wulf
HMI, Berlin
- M. Körfer
DESY, Hamburg
| |
The measurement setup is based on wire scanners, optical fibers mounted symmetrically around the beam line over the full length (30 m) of the undulator section, a signal conditioning unit and a data acquisition system. The fiber sensors along the beam line allow the measurement of the spatial distribution of the scattered beam caused by the wire scanner. At each increment of the wire scanner, the generated Cherenkov light in the fiber sensors - which is proportional to the intensity of the scattered electron shower - is measured. As an improvement, the shower is not only measured at a singular location but over the entire length of the undulator section. Each integral of the generated Cherenkov light along the beam line gives one point of the transversal beam profile. Accomplishing an x-y-scan leads to a two dimensional profile of the beam. The synchronisation with the beam trigger allows the characterization of each bunch. The measured data are visualized in real time and stored in a log file for extended evaluation. The high sensitivity of the system allows an accurate monitoring of the beam profile as well as HALO measurement.
|
|
|
|
| TUPB26 |
Characterisation of the Systematic Effects of the Insertion Devices with Photon Beam Position Monitors
|
photon, polarization, insertion, 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.
|
|
|
|
| TUPC13 |
The new Diode BPM system for ELETTRA
|
controls, vacuum, storage-ring, pick-up |
177 |
| |
- R. De Monte
ELETTRA, Basovizza, Trieste
| |
A new Beam Position Monitor system has been developed at ELETTRA based on an envelope detector. It is a four channel system reading in parallel the four voltages from a button pick-up that adopts a wide-band Schottky diode. The analogue bandwidth of the currently implemented detector is <1kHz which has been adapted to the present application of the system, i.e. a fast beam position interlock to be installed on the ELETTRA storage ring. The upgrade of the ELETTRA BPM which is based on the Libera detector suggested us to add some redundancy on the fast position interlock in order to protect the vacuum chamber from wrong positions / angles of the beam. The data collection scheme, based on a single board computer for each straight section, is presented. Currently, the system has been installed and tested on all the ELETTRA undulator sections; the first running experience is here presented.
|
|
|
|
| TUPC26 |
Button Beam Position Monitors for FLASH
|
pick-up, radiation, electron, linac |
201 |
| |
- J. Lund-Nielsen, N. Baboi
DESY, Hamburg
- W. Riesch
DESY Zeuthen, Zeuthen
| |
Abstract: FLASH (Free Electron Laser in Hamburg) accelerates electron bunches to up to 750 MeV for producing intense, coherent, very short pulses of radiation. Various types of BPMs (beam position monitors) are installed in the facility: cavity and re-entrant-cavity BPMs in the accelerating cryo-modules and button and stripline BPMs in most of the room-temperature sections. The undulator section, where the FEL radiation is produced, is one of the most critical areas of the linac in terms of requirements on the position monitoring. Due to the tight space, button BPMs were chosen for this area. The electronics is based on the AM/PM principle. In the past couple of years these BPMs were commissioned and intensively studied. A few modifications have been made in the electronics, in order to deal with the small signals and the very high frequencies of the ultra-short bunches. In this paper the button-BPMs at FLASH will be presented. The studies made in the RF laboratory and the measurements made on the performance of the BPMs will be discussed.
|
|
|
|
| WEO1A01 |
Sub-ps Timing and Synchronization Systems for Longitudinal Electron Bunch Profile Measurements
|
laser, electron, radiation, diagnostics |
204 |
| |
- A. Winter
DESY, Hamburg
| |
Precise timing and synchronization systems have become an increasingly important topic for next generation light sources. Particularly free electron lasers can emit X-ray pulses with pulse durations down to the few-tens of femtoseconds level. In order to utilize this potential temporal resolution for pump-probe experiments, a precise synchronization of the experimental laser to the X-ray pulse and stabilization of the electron beam arrival time at the undulators are mandatory. This requires a timing and synchronization system which can supply ultra-stable phase references over long distances, thus enabling the temporal stabilization of the electron beam to a sub-100 fs level. Furthermore, a precise timing and synchronization system renders possible extremely accurate measurements of the longitudinal electron bunch profile. This talk will give an overview of the status of existing sub-ps timing and synchronization systems and of systems currently under construction.
|
|
|
|
| WEPB26 |
Transition Thermal Processes In Vibrating Wire Monitors
|
vacuum, photon, radiation, instrumentation |
292 |
| |
- S. G. Arutunian, M. R. Mailian
YerPhI, Yerevan
- G. Decker
ANL, Argonne, Illinois
- G. Rosenbaum
UGA, Athens, Georgia
| |
Dynamic characteristics of vibrating wire monitors (VWM) strongly depend on the media where the wire oscillates, and also on the geometry and materials of the wire and VWM housing. On the basis of a one-dimensional model of heat transfer along the wire, the time characteristics of transition processes of thermal equilibrium profiles are defined for wires of different materials and geometry. To decrease the response time of the VWM, a new scheme of measurement with constant mean temperature is suggested. In addition to the flux of particles/radiation deposited on the wire, the additional DC current maintains a constant wire oscillation frequency. The value of DC current serves as measure of particles/radiation flux.
|
|
|
|