General Meeting Summary 2/18/16

NPS MAGNET UPDATE

• Discussion about yoke

• Designer verified that amount of steel from the pole tip of BNL's Multiparticle Spectrometer is sufficient for the entire NPS magnet including the extra steel required for WACS experiments
• Steel arrived at JLab and is stored in the test lab
• Estimated time until start of construction is ~4 months
• Action item: still need full magnet model - requires support from designer

• Discussion about conductor and coil

• Conductor and suitable power supply (HKS) have been identified, so could start production of coil relatively soon - requires support from designer
• field in gap is good - 5 kG as required, no saturation
• Discussion about fringe fields

• an alternative coil design could reduce fringe fields by factor 4 and also optimize the geometry from the design point of view
• the alternative coil design would use the same conductor, but would go effectively twice around

• Action item: ask for quotation for both coil designs
• Action item: check on other power supplies, e.g., SOS power supply - how close are the parameters?

NPS BACKGROUND STUDIES

• Discussion about the NPS GEANT4 simulation

• Action item: make a comparative study with magnet in vertical and horizontal field configuration and check if there any high dose rates in crystals in the horizontal case

• should change to hydrogen/deuterium target in simulation - assume 10 cm long targets
• do not apply any thresholds in this study

COMPACT PHOTON SOURCE

• Discussion about dump design and radiation control issues, which are a major factor in the design. An important aspect to move forward is to resolve technical issues, e.g.,

• materials needed to construct the dump
• starting from, e.g., the Hall D dump, how could one construct a more compact one that is also servicable

• Discussion about a workshop on the use of an intense photon source and polarized targets

• best time for this seems to be on the scale of 6-9 months - could be adjacent to the next NPS collaboration meeting

• Presentation and discussion about improvement of figure of merit of approved WACS experiment with compact photon source

• taking into account all aspects the improvement is a factor of ~17
• Discussion about impact of heat load in depolarization - how does rotation affect space needed and amount of target material

ITEMS FOR NEXT MEETING:

• Coil quotations (Bogdan)

• Comparative background study (Vardan)

• Other...

NEXT MEETING: THUR 10 MARCH, TIME: 9:00 AM (EST)