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 energy values for photons in BCAL is 15 MeV. Eugene pointed out that for physics analyses, GlueX uses energy 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.
• Richard reminded us that during GlueX we have a secondary collimator followed by a "sweeping" magnet to get rid of off-center lower energy photons and charged particles coming out of primary collimator. Without those the photon beam will not be as clean as GlueX photon beam.

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• Tim is considering ordering tungsten block (actually an alloy) 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 energy photons, namely X-rays, might cause problems to the tracking chambers. This would require GEANT simulations.

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• Tim reported progress on CPS and KPT design.
• Drawing for steel yoke for the CPS magnet are done. Designers (Stephanie) working on the magnet coils. Still planning on the magnet PR this fiscal year.
• Shielding stacking design was discussed on the last design meeting. Various options are being considered at this time.
• KPT drawings are being finalized. There will be a meeting after July 4th with involved parties to check out outstanding issues related to KPT.

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• Mikhail told us that a shipping company will be in Juelich to evaluate the boxes that need to be shipped to JLAB for KFM.

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• Richard had a meeting with UConn machinist regarding the work needed for the KLF Active Collimator. No show stoppers were identified. They are working on transferring AutoCAD drawing to SOLIDWORKS.

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• Igor announced that GWU group funding has been extended to another three years. This funding includes KLF related research by GWU. Congratulations to GWU group !

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• Next meeting is planned in two weeks.

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