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Wednesday 5th December from 2–3pm. Meeting in David Jenkins office RAL R2 4.09. Stephen Brooks, Tristan Davenne and Roger Bennett also in attendence.


  • David Jenkins
    • ✓ (From last time) Information on Ta cladding stress for Bernie Riemer of SNS: stress limits from hipped pure Ta sample test
    • ✓ Find out how much money is available for hardware in PASI targets WP1 Numbers (some multiple of £10k) circulated to Roger
  • Stephen Brooks
    • ✓ (From last time) Forward Tristan's Ta/W HIP stress modelling document onto Bernie Riemer at SNS
    • Start brainstorming document/page for milestone 1.3 on "new" materials
    • ... See if MARS gives gas production in targets, either in TS1,2 models or pure slabs of W or Ta
      • Relate to DPA as (vaguely) requested by Steve Roberts
    This was mentioned at the December 13th RADIATE meeting, with a presentation by Nikolai Mokhov on the MARS models and available data. Sample input files for this calculation will probably be prepared by Nikolai. FNAL may end up doing the simulations instead.
    • ✓ Find out possibility of varying TS2 final quadrupoles in EPB2 to increase or change beam spot size, possibly see prompt effect on neutronics performance, find out if this has been done before Matt Fletcher says this needs to wait until investigations of the TS2 issue conclude, but is potentially a sensible solution



TS2 problems

Work was continuing to diagnose the cause of the radioisotopes recently found in the TS2 water filter. Isotope distribution indicates recently activated and tantalum isotopes appeared to come from tungsten decay chain.

  • ISIS will try to use telescopic rad-hard probe via water channel to see "nose" of target, check for cracking etc.
  • Les Jones wonders if isotopes could be from tungsten-copper electrode used in EDM machining of tantalum water channels (see below on Oxford materials)
  • Three used TS2 targets are in storage awaiting appropriate facilities for cutting and transport
  • Roger asked if it was possible to model tungsten radiation damage, gas production values would be helpful, should ask the Oxford materials group as they also study this (but mostly with reactor neutrons)
  • Possibility of TS2 redesign (or EPB2 change) to mitigate problems we find and improve lifetime

Materials Analysis at Oxford

David Armstrong has the Ta-clad W sample from the HIP process (and Tristan's HIP stress document) and will analyse as he sees appropriate.

  • Les Jones is also preparing a flat sample of EDM-machined tantalum so that David A. can check the surface for impurities and suggest remedies if needed

IWSMT-11 Conference (Ghent, Belgium)

Roger Bennett and David Jenkins had been to Ghent. Any notes or highlight talks obtained from that workshop can be added here.

PASI-funded Hardware

Roger Bennett will eventually look into target temperature diagnostics using line-of-sight and a low-temperature pyrometer. The PASI hardware funds may also be used for new power supplies for the wire test experiment and so on.

PASI Targets Meetings
2012 May 1st Kick-off meeting · August 7th WP1 · October 5th WP1 · October 9th Universities/modelling · December 5th WP1
2013 January 29th WP1 · February 28th Universities/modelling · April 3rd–5th PASI annual workshop ·

December 5th Third General meeting

2014 September 9th Fourth General meeting