DIPAC 2003 - List of Keywords

A B C D E F G H I K L M N O P R S T U W

ion

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, transverse-dynamics	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.

CT10	Beam Diagnostics in the AGOR Cyclotron	diagnostics, instrumentation, cyclotron	80
	S. Brandenburg, W.K. van Asselt, H. Post, H.W. Schreuder KVI, Kernfysisch Versneller Instituut, Groningen, The Netherlands B. Launé IPN, Institut de Physique Nucléaire, Orsay, France
	The beam diagnostics equipment in modern multi-particle, multi-energy cyclotrons for research in nuclear physics is reviewed, using the superconducting cyclotron AGOR at the KVI as an example. An extensive set of diagnostics tools has been integrated already in the design stage. It includes three scanning probes for beam centering, a scanning probe for the measurement of radial and vertical beam oscillations and beamlosses, beam phase pick-ups to optimize isochronism of the magnetic field and profile and current measurements along the beam path through the four movable extraction elements. The operating experience gained since the start-up of the cyclotron in 1996 is discussed for the various diagnostics tools and improvements are described.

PM19	Ionisation Beam Profile Monitor at the Cooler Synchrotron COSY-Jülich	diagnostics, instrumentation, storage-ring, synchrotron	140
	V. Kamerdzhiev, J. Dietrich IKP, Forschungszentrum Jülich, Germany
	For beam profile measurements, a residual-gas ionisation beam profile monitor using a position sensitive micro channel plate (MCP) detector was developed and installed at the cooler synchrotron and storage ring COSY at Forschungszentrum Julich. A parallel ion drift field is maintained in the gap between two electrodes. Residual gas ions are drifted onto an MCP assembly that provides a charge gain of about 10⁷. For online calibration the detector can be illuminated with an α-source. The secondary charge produced from each ion is collected by a wedge and strip anode. After some processing the charge signal is digitized and read out by means of a PC running Cobold PC software. Since COSY operates with beam intensities up to 10¹¹ protons and a vacuum of 10^-9 mbar, there is a high risk of detector damage. The lifetime of the channel plates and the event rate are crucial issues for the profile measurement of intense proton beams. The aging of the channel plates (i.e. inhomogeneous decrease of the gain) were investigated using scanning electron microscope and energy dispersive x-ray microanalysis. Different implemented detector protection mechanisms are discussed. Measurements with electron cooled beams are reported.

PM21	Recent Developments Of The EXCYT Radioactive Beam Diagnostics	diagnostics, ion-source, isotope-production, monitoring	143
	L. Cosentino, P. Finocchiaro INFN-LNS, Laboratori Nazionali del Sud, Catania, Italy
	The EXCYT radioactive beam facility at LNS, based on the ISOL (Isotope Separator On Line) technique, will start producing its first radioactive beams during 2004. We are setting up a suitable high sensitivity diagnostics, in order to guarantee a real time monitoring of the beam parameters (transversal profiles, ion composition and current), offering also the capability to perform the beam imaging at very low beam energy (50 keV). For this purpose, a simple technique based on the use of a thin CsI(Tl) scintillating plate that does not require any amplification system inside the beam pipe, has been employed. Tests performed with stable beams have shown a current sensitivity well below 10⁵ pps, a value that can be improved by adopting a more suitable lens and an intensified and cooled CCD camera.

PT12	Beam Phase Measurements in the AGOR Cyclotron	diagnostics, instrumentation, cyclotron, longitudinal-dynamics	193
	S. Brandenburg, H.W. Nijboer, W.K. van Asselt KVI, Kernfysisch Versneller Instituut, Groningen, The Netherlands
	Beamphase measurement to optimize the isochronism is an essential part of the diagnostics in multi-particle, multi-energy cyclotrons. In the AGOR cyclotron an array of 13 nondestructive beamphase pick-ups is installed. To reduce the large disturbances from the RF-system the measurements are traditionally performed at the 2nd harmonic of the RF-frequency. To further improve the sensitivity intensity modulation of the beam has been introduced. This creates side-bands in the Fourier spectrum, that are completely free of interference from the RF-system. These side-bands contain information on both the beamphase with respect to the accelerating voltage and the number of revolutions up to the radius of the measurement. A specific case is intensity modulation at the orbital frequency, where the side-bands contain only information on the beamphase. Measurements with the different methods will be presented, demonstrating that the intensity modulation strongly improves the sensitivity of the measurement. Useful beamphase measurements can now be made for beam intensities down to 10 nA.