Losses Management Working Group Preliminary Conclusions

1
Losses Management Working Group Preliminary
Conclusions

• Members J.Borbugh, R.Brown, M.Chanel, R.Cappi,
  V.Chohan, D.Cornuet/SL, D.Forkel/TIS,
  M.Gourber-Pace, S.Hancock, J.Hansen/LHC, C.Hill,
  D.Manglunki, L.Rinolfi, H.Schönauer, M.Thivent.
• Guests G.Cuisinier, C.Despas/SL, F.Di Maio,
  A.Ferrari/SL, M.Tavlet/TIS.
• Thanks J.Belleman, H.Klette, E.Metral, G.Metral,
  J.Ottaviani, F.Pirotte, M.Silari, R.Steerenberg...

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Outline

• Mandate
• Why is it a concern?
• Main causes
• Personal doses / Supervised areas
• State of the Hardware
• Recommendations

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Mandate

• Originally To study the problem of the beam
  losses in view of the possible doubling of the
  average beam intensity in the coming years, to
  satisfy the request of future experiments (n-TOF,
  CNGS, )
• Extended to What can be done to improve the
  current situation anyway

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Why is it a concern?

• Staff safety during interventions(induced
  activity from low energy)
• longer intervention/cooling down times
• Hardware preservation(radiation damagefrom high
  energy)
• Good news decrease indose since 1983chart
  from TIS/TE
• Radiation outside machine

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Main causes

• General beam user unawareness
• Dirty operations (injection, CT, capture,
  transition,...)
• Wrong settings (optics, alignment, )

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Personal doses Chart from TIS/RP
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Supervised areas

• TLD distributed around site
• yearly dose monitored divide by 4 for presence
  2000 h/yr
• max for public 1mSv/yr
• Up to 2.42 mSv/y in 1997, average 1.26
• Up to 1.07 mSv/y in 2000, average 0.79
• Keep watching!

8
Hardware tolerance

• 1 Gy 1 J/kg 100 rad
• Electronics stand 100 Gy
• Organic insulators stand 105-106 Gy
• Coil insulators 107-108 Gy

9
Hardware status

• Linac OK
• PSB OK
• New H1 system less lossy
• Watchdog implemented
• Most concern in the PS
• Vacuum, RF kickers no HW problembut concern
  on staff!

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Hardware status

• PS magnet (100,7,8,38, 62,83, 92)
• average 3E6 Gy (problems start 1E7 Gy expected
  in 10 yrs)
• pfw (i.e in 31, L1 and L2 have R)

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Hardware status

• SEH31 is main concern
• cable usually breaks before end of run
• Instrumentation
• mostly hidden under concrete

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Recommendations

• Awareness Implement SW tools
• PS watchdog
• Losses pattern logging
• Resurrect transmission histogram display
• Thorough analysis of losses
• started on TOF, AD (GM, EM ...)
• should continue on SFTPRO
• units problem W/m? ppp?

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Recommendations

• Magnet change 1 week (!)
• preventive
• risk but no guarantee
• when it fails
• higher doses
• loss of one week of physics
• Magnet repair 1 month
• spares exist for each unit configuration

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Recommendations

• SEH 31
• Oil change every 3 monthsimproved, automatic
  system to be studied
• Foresee cable change (4.5 days, including
  cooldown time) after 6 months
• New CT

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Recommendations

• Database of dose/equipment
• TIS/TE happy to provide custom monitors
• Increase number of RPLs
• Collimator study
• trap uncaptured/unejected particles instead of
  losing on SS1/SS16-26