• Higher leakage to IR6 from IR7 in B1H loss maps from 18cm beta star
• Simulation of BLM responses in Q4 and Q5 from impacts on TCSP/TCDQ collimators, to see if there is risk of quenching the magnets
• Belen says that in 2023 ion run there was also observed higher signals in IR6 with B2, at that moment the TCSP jaw was opened to alleviate the losses
  • A possible increase of up to a factor of 5 for RS09 was agreed
• TCDQ only has one jaw (9 meters long), TCSP has two (only one meter down)
• Some meters below a mask, TCDQM, then the first superconducting magnet Q4, some more meters downstream (about 20) the Q5
• Impacts on TCDQ: 2e-12 Gy/p Q4, 1e-12 Gy/p Q5
• Impacts on TCSP: 6e-12 Gy/p Q4 and Q5
  • Makes sense as TCSP is shorter, so less absorbing, higher BLM response expected downstream
• MF = 0.4 for the BLMs at Q4, Q5
• TCSP and TCDQ losses at Q4/Q5 dump threshold estimated (for applied thresholds)
• Q4 has the mask, so power deposition per proton lost is lower than in Q5
• Q5 has a peak of power deposition in beginning of magnet
• Both magnets of the MQY type at 4.5K
  • Q5 gets to 3500A
  • Q4 gets between 2500 and 3000A
• Maximum power deposition in Q4 and Q5 at which we are expected to dump calculated, higher for Q5 as different BLM response
  • Quench level depends on magnet current
  • There should be some margin, but there is still some uncertainty
  • Could allow for a factor of 2 probably, a factor 5 would be too much
  • From document from Andrea 
    • 37 mW/cm3 quench level for 3000A at 7 TeV, will have to check for 6.8 TeV
• See how to apply this change -> so that master threshold is at quench level?
• Anton shows Run 2 studies that show that the leakage to IR6 from IR7 seems to decrease with higher loss rates
• Daniele asks why for B2H it is not expected to reach the thresholds at the same IR7 power loss even though there seems to be similar inefficiency during loss maps
  • Fabian shows that for the equivalent B2 BLM, the response during B2H loss map seems to be around 3 times lower
  • Belen and Anton remind that one should also consider that the responses in IR7 also vary for B1 and B2