Keyword: photon
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THO3C01 Optical Transition Radiation for Non-relativistic Ion Beams ion, target, radiation, electron 580
 
  • B. Walasek-Höhne, C.A. Andre, F. Becker, P. Forck, A. Reiter, M. Schwickert, R. Singh
    GSI, Darmstadt, Germany
  • A.H. Lumpkin
    Fermilab, Batavia, USA
 
  In this contribution, recent results of Optical Transition Radiation (OTR) measurements with a non-relativistic heavy-ion beam will be presented. This feasibility study was prompted by previous measurements [1] and the theoretical estimation of expected signal strengths for the GSI linear accelerator UNILAC. For this experiment, an 11.4 MeV/u Uranium beam was chosen to investigate OTR signal from several target materials and to evaluate the working regime for the used experimental setup. The OTR light was either observed directly with an Image Intensified CCD camera (ICCD) or indirectly via a spectrometer for wavelength resolved data. A moveable stripping foil allowed measurements with two different ion charge states. The theoretical q2 dependency of the OTR process predicts a six-fold increase in light yield which was confirmed experimentally. Obtained OTR beam profiles were compered to SEM-Grid data. Moreover, ICCD gating feature, as well as the emitted light spectrum ruled out contribution of any background sources with longer emission time constant e.g. blackbody radiation.
[1] C. Bal et al., "OTR from Non-relativistic Electrons", Proceedings of DIPAC03, PM04, Mainz Germany.
 
slides icon Slides THO3C01 [1.905 MB]  
 
THO3C05 Fiber Based BLM System Research and Development at CERN radiation, beam-losses, electron, quadrupole 596
 
  • S. Mallows
    The University of Liverpool, Liverpool, United Kingdom
  • E.B. Holzer, S. Mallows, J.W. van Hoorne
    CERN, Geneva, Switzerland
 
  The application of a beam loss measurement (BLM) system based on Cherenkov light generated in optical fibers to a linear accelerator with long bunch trains is currently under investigation at CERN. In the context of the Compact Linear Collider (CLIC) study, the machine protection role of the BLM system consists of its input to the \lqnext cycle permit\rq. In between two cycles it is determined whether it is safe to commit the machine for the next cycle. A model for light production and propagation has been developed and validated with beam measurements. Monte Carlo simulations of loss scenarios established the suitability in terms of sensitivity and dynamic range. The achievable longitudinal position resolution of the system, considering that the bunch trains and the optical fiber length are comparable in size is discussed.  
slides icon Slides THO3C05 [3.846 MB]