• U. Iriso, G. Benedetti, F. Peréz
  CELLS-ALBA Synchrotron, Cerdanyola del Vallès

One of the key diagnostics instruments during the ALBA Linac commissioning was the screen monitors, which allowed control of beam size and position. These screen monitors are equipped with a YAG and an OTR screen. This paper describes our screen monitor setup and the experience with both types of screens.

• S.G. Arutunian, Zh.S. Gevorkian, K.B. Oganesyan
  YerPhI, Yerevan

Diffusive Radiation (BR) is originated by the passage of charged particles through or near a randomly inhomogeneous medium. DR appears when the conditions for multiple scattering of pseudophotons are fulfilled in the medium. Such a situation can be realized when a charged particle slides over a rough metallic surface. One of the important properties of DR is that the emission maximum lies at large angles from particle velocity direction. Therefore it can be used for detection of beam touch to the accelerators vacuum chamber wall in case when generated photons will be observed on the opposite side of the vacuum chamber. Such a diagnostics can be especially useful for observation of storage ring beams halo. Corresponding proposal is presented in the paper.

• M. Olvegård, A.E. Dabrowski, S. Döbert, T. Lefèvre
  CERN, Geneva
• E. Adli
  University of Oslo, Oslo

The CTF3 provides high current (28A) high frequency (12GHz) electron beams, which are used to generate high power radiofrequency pulses at 12GHz by decelerating the electrons in resonant structures. A Test Beam Line (TBL) is currently being built in order to prove the efficiency and the reliability of the RF power production with the lowest level of particle losses. As the beam propagates along the line, its energy spread grows up to 60%. For instrumentation, this unusual characteristic implies the developments of new and innovative techniques. One of the most important tasks is to measure the beam energy spread with a fast time resolution. The detector must be able to detect the energy transient due to beam loading in the decelerating structures (nanosecond) but should also be capable to measure bunch to bunch fluctuations (12GHz). This paper presents the design of the spectrometer line detectors.

• P.S. Yoon, D.P. Siddons
  BNL, Upton, Long Island, New York

We have developed a photodiode-based X-ray beam-position monitor with high-spatial resolution for use on the future beamlines at NSLS-II. A ring array of 32 Si PIN photodiodes were fabricated for a photon sensor, and a newly-designed HERMES4 ASIC die was integrated into the data-acquisition system. A series of precision measurements for electrical characterization of the Si-photodiode sensor and the ASIC die demonstrated that the inherent noise is sufficiently below tolerance levels. Following up with a series of modeling efforts including geometrical optimization, we have built prototype detectors. In this paper, we present the development of the new state-of-the-art X-ray BPM and experimental measurements performed on the existing X12A beamline at NSLS.

• T. Milosic, P. Forck
  GSI, Darmstadt
• D.A. Liakin
  ITEP, Moscow

A device for accessing the longitudinal phase space at low energy sections (1.4 MeV/u) of the GSI heavy ion LINAC is presented. In the course of the FAIR project optimizations of the existing facility at GSI are required. Integral information for the optimization process is extracted by the knowledge of the six dimensional phase space. Opposed to the transversal parameters it is particular difficult to access the longitudinal degree of freedom at low energies. The presented interceptive measurement is based on the coincident detection of single particles by means of two detectors: The first detector provides measurement of secondary electrons emitted from a thin Al-foil by the impinging ion beam. Secondly, after a drift of 80 cm beam particles are registered directly by a fast diamond detector. This contribution describes the measurement setup in detail including the principle of particle number attenuation by Rutherford scattering in the Ta foil. The achievements concerning the required timing resolution are presented and the investigations are accompanied by recently recorded data.