KLF beamline meeting - June 28, 2024

Agenda

• Announcements

• Photon beam in the hall during KLF? (ig, Sean)

  • Timing & energy calibration requirements for the calorimeters (ig)

• Tungsten blocker length (Vitaly,Tim)

  • Tungsten procurement options ET95 and ET90
  • K_long flux z-distribution from Vitaly's FLUKA model
  • Approximate EM shower z-distribution ,

• CPS & KPT design progress (Tim)

  Statement regarding thermal cycling of the targets receiving >1 KW power.

• Updates on Flux Monitor (Mikhail)

• Updates on Active Collimator (Richard)

• Any other business

Minutes

Present: Igor, Hovanes,Vitaly, Edy, Tim, Eugene, Ig, Richard, Mikhail, Marshall, Chris, Alex

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• Hovanes introduce the potential reason why it might be needed to have to have a possibility to send photon beam to the main hall during KLF.
  1. Energy calibrations
  2. Timing calibrations
• Igal briefly discussed the energy calibrations for GlueX and how they might be utilized in KLF. Based on information he had, the non-linearity corrections in the energy calibrations will not be negligible at lower photon energies.
• Mikhail confirmed that for hyperon physics the photon energies are expected to be below E<500 MeV. He also believes that 20 MeV mass resolution for $\pi ^{0}$ mass should be OK.
• Igal told us that the minimum values for photons in BCAL is 15 MeV. Eugene pointed out that for physics GlueX uses cuts at 50 MeV. The minimal photon energy value for FCAL is much larger, about 150 MeV to 200 MeV.
• igal estimates that in order to have full calibrations, including non-linear corrections, would require about a week of beam time at 100nA and $10^{-4}$ radiator. For simpler calibration without non-linear corrections one day of beam might suffice.
• The timing calibrations would need only eight hours of photon beam at 100nA and $10^{-4}$ radiator.
• Mikhail is looking at the possibility of energy calibrations using neutrons already present in the K-long beam. Mikhail will send files form his simulations of $\pi ^{0}$ events to Igal for him to evaluate how good they are for energy calibrations.
• Tim discussed what such a photon beam would entail in terms of time and costs. At this time he only had some rough ideas what would need to be done. Tim thinks that the transition from such a photon beam to K-long setup would take about a couple of days. Also, it would require about a month of additional engineering to accommodate requirement of having collimator, profiler, and AC during the photon beam time.
• Beni asked if a motorized system can be used to move the KPT assembly. Tim answered that it is in general possible. Care must be taken to make sure that system stays operational in that high radiation environment.
• No decision taken at this time on photon beam topic due to insufficient information.

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• Tim is considering ordering tungsten block for KPT from two options: ET90 ($\rho =17~{\frac {g}{cm^{3}}}$) and ET95 ($\rho =18~{\frac {g}{cm^{3}}}$).
• Vitaly pointed out that the simulations have been done using pure tungsten with $\rho =16.3~{\frac {g}{cm^{3}}}$. He estimated that the ET95 would reduce the K-long flux by less than 10% with respect to the $\rho =16.3~{\frac {g}{cm^{3}}}$ tungsten, which is not a big deal.
• Hovanes pointed out that the reduction of the leakage from the electromagnetic shower is significantly more.
• At the end there was a consensus that ET95 ($\rho =18~{\frac {g}{cm^{3}}}$) tungsten block should be fine.
• Eugene pointed out that the effects of the leakage through the blocker in terms of the impact of the detector performance should be evaluated. In particular, the low wnrgy photons, namely X-rays, might cause problems to tracking chambers. This would require GEANT simulations.

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