General Meeting Summary 5/28/20

PARTICIPANTS: Charles Hyde, Bogdan Wojtsekhowski, Arshak Asaturyan, Vardan Tadevosyan, A Comer, Hamlet Mkrtchyan, Alexandre Camsonne, Paulo Medeiros, Steven Lassiter, Vladimir Berdnikov, Carlos Munoz-Camacho, Jacob Murphy, Marie Boer, Hakob Voskanyan, Rolf Ent, David Hamilton, Julie Roche, Tanja Horn

MAGNET

Work ongoing

FRAME (Carlos)

• Photos from pre-lock down illustrate the assembly status - some of the smaller components were assembled off-site during lock down and are ready to be included when possible
• Small number of people allowed part time on site now and some assembly can continue, subject to new distancing rules etc.

NPS LOGO

• Presentation of the logo planned to be included on the NPS frame
• Optimizations and other suggestions welcome

CABLING

• NPS cable making is ongoing at JLab (off-site)

• SMA for signal
• Fischer for HV
• Samtec HV

• How to test cables?

MECHANICAL DESIGN (Paulo, Steven L.)

• Released requisitions for structural components (platform)

• Expect all other parts to be submitted by end of week

• Prepared and passed on step files for corrector magnet

• Results from field integral calculations (Bogdan)

• Significant integral BdL (~30-40kGauss) without corrector, need to compensate for field integral
• Field integral not large - can build corrector without much problem (cost ~$10k)
• Corrector cannot compensate for shift in position, still have significant displacement - shift is on level of 4cm creating a background: low energy particles will scrape beam line
• To address this issue would like to shift corrector 15cm downstream - requires to modify a pipe (~$3k)
• Discussion:

• Corrector in beam line after magnet has been difficult traditionally - cables, power supplies space issues, radiation of components
• Flux exclusion tube vs. corrector magnet? - Is there enough space? Tube seems more complex and complicated than corrector
• Installation of corrector: clamped on beam line, no separate support
• Current density: 200-300 A/cm2, no water cooling - the latter is important since located in a high radiation area
• Corrector is a protection of beam dump - magnet controlled by MCC, deflection without magnet of primary beam is 6cm at beam dump
• Can corrector magnet hang off the NPS magnet and rotate with the magnet?

• General consensus to proceed with the corrector magnet design

HV DIVIDER - ANODE CURRENT

• Review of the issue and discussion of possible solutions

• Need to reduce PMT gain - 10^6 too much and even 10^5 too much, 10^4 might be fine, but then need to figure out how to do amplification

• Bogdan's slides summarize several options to reduce anode current, but need feedback from Fernando's group on base modifications

• Action Item: Meet with Fernando on base modifications

NEXT MEETING: THURSDAY 11 JUNE AT 9AM (ET)