WG 5 – Instructions CERN IRRAD

CERN IRRAD 24 GeV Proton beam irradiations:

• Organized DRD3 batches in 2025: May and September (fixed target, up to 1e16)
  • We will issue a DRD3-wide call in April (to several common fluences)
  • If possible, try to join the DRD3 batch to reduce load for IRRAD staff
• Special requests (scanning, >1e16, etc) should be communicated to IRRAD by April 2025

IRRAD website

Beam parameters:

• Beam dimensions:
  • standard size: ~12×12 mm² (FWHM)
  • spot size from ~6×6 mm² to ~20×20 mm² (FWHM)
  • keep in mind that beam profile is a Gaussian – there will be fluence gradients
• Beam intensity
  • protons are delivered in spills of ~5e11 p
  • number of spills/frequency depends on CPS
  • Typical CPS : 30-37s
• NIEL Fluence conversion:
  • In Silicon: 1 p/cm² = 0.63 MeV neq/cm²

Sample preparation:

• Sample preparation is the responsibility of Users
• IRRAD can provide Cardboard Holders and Kapton Foil for sample mounting
• Fixed target samples should be mounted on standard Cardboard Holders
  • These are inserted in the IRRAD sample mount. Beam passes through the Cardboard Holder center by design.
  • The Cardboard Holders come with different cutout openings (5×5 mm, 10×10 mm, etc.)
    • Samples are inserted into the opening
    • The opening is covered with Kapton Foil on both sides
    • Kapton foil has to be fastened to the cardboard holder with kapton tape
    • This ensures the sample is not with contact with any glue, which can react with the sample surface (Kapton Foil is radiation hard)
• All samples have to be registered in the IRRAD Data Manager