CERN Accelerating science

  Improved ion sources and beam diagnostics for FAIR and SPIRAL2
  by Peter Forck (GSI) and Christophe Peaucelle (IN2P3) with Agnes Szeberenyi (CERN)

Fig 1, left: An image of the bunch shape as recorded at the GSI LINAC with a beam of U28+ ions at 11.4 MeV/u. The plot shows the 70 mm MCP original image created by residual gas electrons on top and the projection to the horizontal axis results in the bunch shape below. Image credit: GSI.
Fig 2, right: Low-energy beam transport line of SPIRAL-2 with PHOENIX V2 ion source during commissioning. Image credit: LPSC/IN2P3

Under the CRISP project framework, WP3 aims at developing improved ion sources and beam diagnostics  for SPIRAL2 atGANIL and FAIR Proton LINAC at GSI. Modern high power proton and ion LINACs aim for an effective acceleration and low RF-power consumption. This is realized by a high electric field gradient and non-standard beam dynamics settings.

SPIRAL2 is based on the detection of X-rays as emitted from a thin tungsten wire inserted in the beam path. These X-rays are detected by a fast Multi-Channel Plate mounted outside of the beam path. Conclusive tests at Institute de Physique Nucleaire in Orsay and GANIL lead to the realization of a compact device. The FAIR Proton LINACӳ monitor is based on the detection of secondary electrons as liberated from the residual gas molecules by beam impact. By the electric field within an RF-deflector the electrons are bent to transform the time information to a difference in space.

FAIR and SPIRAL2 facilities need both a high performance electron cyclotron resonance ion source (ECRIS) to create the high intensity beams. PHOENIX V2, a 18 GHz room temperature ECRIS developed by LPSC Grenoble will be the starting heavy ion source on SPIRAL 2. An evolution to PHOENIX V3 is being studied in order to increase the beam intensity by a factor of 2. The first beam with PHOENIX V3 is scheduled for November 2013.

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