Difference between revisions of "Technical Board Meeting Oct 23, 2023"

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(Attendance)
(Attendance)
Line 51: Line 51:
  
 
Present:
 
Present:
Kent Paschke, Chair (MOLLER Scientific Coordinator)
+
*Kent Paschke, Chair (MOLLER Scientific Coordinator)
Krishna Kumar (MOLLER Spokesperson)
+
*Krishna Kumar (MOLLER Spokesperson)
Mark Pitt (Deputy Spokesperson, MOLLER-NSF Project Coordinator)
+
*Mark Pitt (Deputy Spokesperson, MOLLER-NSF Project Coordinator)
Ruben Fair (DOE Project Manager)
+
*Ruben Fair (DOE Project Manager)
Klaus Dehmelt (Deputy DOE Project Manager)
+
*Klaus Dehmelt (Deputy DOE Project Manager)
Michael Gericke (MOLLER-CFI Project Coordinator)
+
*Michael Gericke (MOLLER-CFI Project Coordinator)
Mark Jones (Hall A Leader)
+
*Mark Jones (Hall A Leader)
David Armstrong (Elected Executive Board Member)
+
*David Armstrong (Elected Executive Board Member)
Dave Meekins (L2 CAM: Target)
+
*Dave Meekins (L2 CAM: Target)
Carl Zorn (L2 CAM: Detectors)
+
*Carl Zorn (L2 CAM: Detectors)
Ciprian Gal (L2 CAM: Infrastructure)
+
*Ciprian Gal (L2 CAM: Infrastructure)
Robert Michaels (L2 CAM: DAQ)
+
*Robert Michaels (L2 CAM: DAQ)
Vladimir Berdnikov (L2 CAM: Installation)
+
*Vladimir Berdnikov (L2 CAM: Installation)
Silviu Covrig (Working Group Convener: Target)
+
*Silviu Covrig (Working Group Convener: Target)
Dustin McNulty (Working Group Convener: Integrating Detectors)
+
*Dustin McNulty (Working Group Convener: Integrating Detectors)
Paul King (Working Group Convener: DAQ)
+
*Paul King (Working Group Convener: DAQ)
Jim Napolitano (Working Group Convener: Polarimetry)
+
*Jim Napolitano (Working Group Convener: Polarimetry)
Eric Sun (joined for technical assistance)
+
*Eric Sun (joined for technical assistance)
  
 
Not attending:
 
Not attending:
Juliette Mammei (Executive Board International Representative)
+
*Juliette Mammei (Executive Board International Representative)
Paul A Souder (Elected Executive Board Member)
+
* Paul A Souder (Elected Executive Board Member)
Robin Wines (Project Engineer)
+
* Robin Wines (Project Engineer)
Mike Dion (L2 CAM: Spectrometer)
+
*Mike Dion (L2 CAM: Spectrometer)
Caryn Palatchi (Working Group Convener: Polarized Beam)
+
*Caryn Palatchi (Working Group Convener: Polarized Beam)
Nilanga Liyanage (Working Group Convener: Tracking Detectors)
+
*Nilanga Liyanage (Working Group Convener: Tracking Detectors)
Rakitha Beminiwattha (Working Group Convener: Simulations)
+
*Rakitha Beminiwattha (Working Group Convener: Simulations)
Yury Kolomensky (Working Group Convener: Physics Extraction)
+
*Yury Kolomensky (Working Group Convener: Physics Extraction)

Revision as of 17:14, 23 October 2023

Back to Main Page >> Technical Board

Technical Board Meeting September 18, 2023 << >> Technical Board Meeting October 30, 2023

Online: see email

Agenda

  • Scattering chamber exit window design and lead time [Dave Meekins] Slides
  • Effect of Aluminum Scagttering chamber exit window on MOLLER backgrounds Ciprian docdb:1172
  • Physics evaluation of Drift pipe end cap design change [Kent] docdb:1171

Minutes

Drift pipe end:

  • Drift pipe end cap was "dish" shaped, about 1" thick, to avoid an excessively thick wall. This added cost and schedule concerns, which can be relieved with a flat, 3" thick flange.
  • There is a 5" thick wall just upstream of this, at the end of the downstream torus vacuum enclosure.
  • Simulations confirm this understanding: the additional thickness at the upstream end of the drift pipe do not add significantly to backgrounds.
  • There might even be a very small benefit, but at this level the statistical significance of the simulation is not fully sufficient.


Scattering Chamber Exit Window:

Cip: Physics simulation

  • added Al window at the scattering chamber exit
  • found that 400micron roughly doubles the total Al contributions from the target windows. The additional contribution is consistent with linear scaling with thickness of the scattering chamber windown
  • "deconvolution" results don't degrade, but this is based on assumptions of Al fractions and asymmetries being perfectly known
  • In fact, Al corrections will be uncertain at the 10% level due to uncertainty in the Al asymmetry
  • Qweak measured APV to 10% (Note in chat: SM coupling known better than this, so this would be a worst-case limit for knowledge of asymmetry.)
  • DA: what about uncertainty in rate?
    • rates with gas-filled target are hard to get, since knowing the gas density was difficulty
    • KK: simulation is required, other studies will be possible
    • KK : Be window would be very valuable to have, even if installed later. So we should keep this development alive, even if we got with the Al window to start Run1.

Meekins:

  • delivery is not going to be available from previous vendor.
  • Materian (now purchased and absorbed into another company) will no longer provide flanges.
    • Al is easy, but Be is difficult
    • Be brazing is possible, (in conversation with WessDel) but this is also challenging to move forward due to inconsistent vendor response.
      • This would require the experiment is accept brazing alloy of zinc/Al
    • Be: better thermal conduction, better cyclic loading, low Z for backgrounds
  • Aim to prepare to handle 20psi load if H2 cell failure. 15pse for atmosphere
  • Dishing is required, allows for relief of mechanical stress under thermal load
  • This design has 10 mils in vacuum window, 25 mils in 3" diameter for accepted scattered particles
  • Old window, was about 1 calendar year replacement cycle at 10trips/hr
    • new design is probably much better, but not so clear yet. Now looking at 70k cycles compared to 45k in flat design.
  • status: "Its done", this can be built in machine shop.
  • May need to make several to meet thickness goals, with reasonably small variation. There are measurement tools to know what we have well.
  • KK: Summary from the experiment side: we would prefer Be window to improve physics, but we are ok with this Al design even for full experiment.

Attendance

Present:

  • Kent Paschke, Chair (MOLLER Scientific Coordinator)
  • Krishna Kumar (MOLLER Spokesperson)
  • Mark Pitt (Deputy Spokesperson, MOLLER-NSF Project Coordinator)
  • Ruben Fair (DOE Project Manager)
  • Klaus Dehmelt (Deputy DOE Project Manager)
  • Michael Gericke (MOLLER-CFI Project Coordinator)
  • Mark Jones (Hall A Leader)
  • David Armstrong (Elected Executive Board Member)
  • Dave Meekins (L2 CAM: Target)
  • Carl Zorn (L2 CAM: Detectors)
  • Ciprian Gal (L2 CAM: Infrastructure)
  • Robert Michaels (L2 CAM: DAQ)
  • Vladimir Berdnikov (L2 CAM: Installation)
  • Silviu Covrig (Working Group Convener: Target)
  • Dustin McNulty (Working Group Convener: Integrating Detectors)
  • Paul King (Working Group Convener: DAQ)
  • Jim Napolitano (Working Group Convener: Polarimetry)
  • Eric Sun (joined for technical assistance)

Not attending:

  • Juliette Mammei (Executive Board International Representative)
  • Paul A Souder (Elected Executive Board Member)
  • Robin Wines (Project Engineer)
  • Mike Dion (L2 CAM: Spectrometer)
  • Caryn Palatchi (Working Group Convener: Polarized Beam)
  • Nilanga Liyanage (Working Group Convener: Tracking Detectors)
  • Rakitha Beminiwattha (Working Group Convener: Simulations)
  • Yury Kolomensky (Working Group Convener: Physics Extraction)