| Paper |
Title |
Other Keywords |
Page |
| CT02 |
Single Shot Measurements of the 4-Dimensional Transverse Phase Space Distribution of Intense Ion Beams at the UNILAC at GSI
|
diagnostics, instrumentation, linac, ion |
56 |
| |
- L. Groening, W. Barth
GSI, Gesellschaft für Schwerionenforschung, Darmstadt, Germany
- D.A. Liakin
ITEP, Institute for Theoretical and Experimental Physics, Moscow, Russia
| |
The UNILAC is used as an injector for the synchrotron SIS. It is designed
to fill the synchrotron up to its space charge limit. The upper limit for
the useful beam emittance of the UNILAC is given by the finite acceptance
of the SIS during the injection process. In order to remain within this
acceptance the emittance growth during beam acceleration and
transportation due to space charge effects must be minimized by applying
an appropriate beam focusing. Therefore, the influence of the magnetic
focusing strength on the beam emittance growth was investigated
experimentally for different beam currents. Measurements of transverse
phase space distributions were performed before and after the Alvarez
accelerator with a periodic focusing channel, respectively. In order to
perform such a wide parameter scan within a reasonable time with respect
to machine stability, the pepper pot technique was applied. The pepper
pot method allows for single-pulse measurements. For comparison several
measurements using the slit-grid technique, which averages over many
pulses, were performed. Both transverse planes were measured
simultaneously. Using two pepper pot devices more than 60 single shot
measurements of the full 4-dimensional transverse phase space
distribution were performed within 8 hours. In this paper we report on
the results of the measurements and we compare them to beam dynamic
simulations and we give an outlook on further developments on pepper pot
devices.
|
|
|
|
| CT08 |
Capabilities of the ELETTRA/SLS Multibunch Feedback Electronics
|
diagnostics, instrumentation, feedback |
74 |
| |
- M. Dehler, R. Kramert, P. Pollet, D. Bulfone, M. Lonza
PSI, Paul Scherrer Institut, Villigen, Switzerland
| |
Due to the unavailability of commercial ADC and DAC boards, first
commissioning of the transverse multi bunch feedback was done in the last
year using loaned equipment from Sincrotrone Trieste. In order to remedy
that situation, development of ADC and DAC VME boards was started. The
boards do a 500 MS/s data conversion with an 8 bit resolution. The ADC
and DAC circuits are separate modules containing their own one to four
de-/multiplexing electronic reducing the data rate to 125 MS/sec. The
following stage being a common design to both ADC and DAC allows data
recording and play back using on board RAM and allows freely programmable
multiplexing/demultiplexing ratios of one to five to one to twelve. The
digital data streams flow via Front Panel Digital Ports (FPDP). A special
design criterion were low system latencies ensuring a high feedback
efficiency. Apart from lab tests, we report on full feedback system test
and show the feedback performance in the transverse and longitudinal
planes.
|
|
|
|
| PM03 |
Studies of OTR Angular Distribution on CTF2
|
CLIC, diagnostics, instrumentation, optics |
92 |
| |
- E. Bravin, T. Lefèvre
CERN, Geneva, Switzerland
| |
Today, Optical Transition radiation (OTR) is widely used in beam
diagnostics. The most common application is the imaging of the transverse
and longitudinal beam profiles. Other beam parameters like divergence and
energy can also be deduced by observing the angular distribution of the
OTR emission (“Donuts”). In order to investigate the possibilities
and the limits offered by this technique we have performed a test on the
48 MeV, 1 nC electron beam of the CLIC Test Facility 2 (CTF2).
Beam divergences between 2 and 6 mrad were measured with an accuracy of
few percent. A good agreement was also found between the energy
measurements obtained with a classical spectrometer and the OTR based
technique. We conclude describing some possible future applications of
OTR based diagnostics for CLIC.
|
|
|
|
| PM04 |
OTR from Non-Relativistic Electrons
|
CLIC, diagnostics, instrumentation, optics |
95 |
| |
- C. Bal, E. Bravin, E. Chevallay, T. Lefèvre, G. Suberlucq
CERN, Geneva, Switzerland
| |
The CLIC Test Facility 3 (CTF3) injector will provide pulsed beams of
high average current; 5 A over 1.56 μs at 140 keV. For transverse beam sizes
of the order of 1mm, as foreseen, this implies serious damages to the
commonly used scintillating screens. Optical Transition Radiation from
thermal resistant radiators represents a possible alternative. At low
energy the OTR emission is feeble and distributed over a large solid
angle. In order to investigate the feasibility of such a diagnostic
studies have been carried out on a test 80 keV photo injector. The
experimental set-up is described and the results are compared to the
calculations based on the OTR emission theory. Our conclusions for the
design of the CTF3 injector profile monitor are also given.
|
|
|
|
| PM06 |
An Improved PLL for Tune Measurements
|
diagnostics, controls, instrumentation, synchrotron |
101 |
| |
- O. Berrig
CERN, Geneva, Switzerland
| |
The key element determining the dynamic performance of such a PLL is the
phase detector between the beam oscillation and the internal oscillation.
Most circuits use a quadrature phase detector, for which the high
frequency carrier at twice the excitation frequency is attenuated by a
low-pass circuit. The remaining ripple of this component contributes to
the bandwidth/noise performance of the PLL.
In this paper we propose an alternative solution for the filter, notably
an adaptive notch filter. We explain in detail design considerations and
the resulting improvements in PLL bandwidth and/or noise figure.
|
|
|
|
| PT23 |
Transverse Emittance Measurements at the Photo Injector Test Facility at DESY Zeuthen (PITZ)
|
diagnostics, emittance, free-electron-laser, linac, PITZ |
225 |
| |
|
|