Status of Engineering Preparations for CD2/3A nEDM Collaboration Meeting – MIT Bates Jan Boissevain November 2, 2007

CD2 Preparations 1.2 Beam-line Design - starts ~2/’ Cryovessel –Beam-line interface – separate vacuum –Mumetal Shield interface – support structure to rails –Kerr Effect interface –ASME pressure vessel – “Tee” biggest challenge 1.3 Dilution Refrigerator –3He pumping system – likely 2 each EH EH GX100L (use both for cool down and one for “normal” flow rates) => Could run dual use cryostat at the same time –Maximum LHe consumption: ~20 liters/hour –1K Pot pump system yet to be determined

Vacuum Can “Tee” ~Support Post Locations Central Volume Supports Kerr Effect Probe Flanges

1.3 Helium Liquefier –JLab advice: <1ppm impurities –Linde L70 (Turbine Expander) – best choice for nEDM –To Do: Ernie and Jan will generate a block diagram and physical layout to be blessed by JLab 1.3 Central Volume –Met with Jeff Eischen and Brandon Angell to discuss plans for finite element analysis –Met with Stan Smeltzer and discussed constraints on design of end cap – manufacturing issues –Potential vendor located in Lafayette, CO –Generation of the end cap in process CD2 Preparations (2)

CD2 Preparations (3) 1.4 3He Services –Still at the concept stage with the default method to move the 3He – heat flush –Desirable Feature: Pressurization This feature will require a very fancy inline valve –Holmium heat sink probably still required –Space available appears to be adequate Valve Progress – UIUC (Larry Bartoszek)

CD2 Preparations (4) 1.5 Mu-metal Shield –Chris Daurer now working on support structure. –Cryovessel still fits inside 1.5 Magnet Package –Larger, B0 now Dia. 1.3m x 4.3m long (14’) – fixes error in CDR –Problem getting long G10 tubes – Precision Cryogenics makes tubes longer than 4’ using Al rings => special composite tubes $$$ –If radiation cooling does not work, then need more windows for Kerr Effect apparatus

CD2 Preparations (5) 1.6 Central Detector –Possible solution for light guide interface with enclosure end cap –Kerr Effect Probe requires hole in HV return and “window” in measurement cell

CD2 Preparations (6) 1.7 Slow Controls 1.8 Infrastructure –Working with ORNL to define a suitable experimental hall for nEDM