Time: 8am PT/11am ET/5pm CET Zoom link: https://uzh.zoom.us/j/5166204490?pwd=VUt1VmFLVmJsYTExeXJka0JwbUlIQT09

Attendance: Matt, Dan M, Andrey, Alex, Kamil, Emma, Iva, BP, Scott

Agenda:

• Vibration specification - Matt slides
  • Need to suppress all peaks 75-110 Hz to 10^-6-10^-7 PSD g/sqrt(Hz)

• Fridge Internal Weights - EmmaSpreadsheet
  • Bluefors LD 400 conclusions are: the weights are too heavy
• Updated simulations and radiopurity requirements - Alex
  • Updated background activity from Edelweiss, SuperCDMS etc
  • Updating in particular Ti double the background about
  • Underground copper or ancient lead is our only way to improve

Other points:

• Andrey - Design studies for a circular/chamfered design
  • 30% of weight savings
  • Simplified the pieces, might be easier to machine
  • Made design of individual pieces easier to manufacture
  • Screenshots: https://drive.google.com/drive/folders/1g1doxwZ6cujvktOinU10wnV-EWGRsD5N

To Do:

• Approximate design of vibration decoupler
• Andrey will detail new drawings of 'otcagon design' and sends them to UZH
• Alex adding ancient lead only sims and discussing with Julien

We should also discuss talk information Julien needs for Oxford Instruments