1. Brad Moore M.S. Student Room: 1337 507 884 9258 Hometown: Rochester, MN Thesis: Development of a Passive Check Valve for Cryogenic Applications

2.  Astrophysics missions employing Microcalorimetry and Transition edge sensors have a need for sub- Kelvin (<1K) cooling.  A Cold Cycle Dilution Refrigerator (CCDR) provides an alternative to the current space based sub-kelvin cooling - Adiabatic Demagnetization Refrigerators or LHe3 Cryostats.  The CCDR provides cooling through the endothermic mixing of He3-He4 isotopes at low temperatures.  A reversible paramagnetic pump drives the flow through the cycle, however the flow provided is oscillating and must be rectified through the use of check valves. Background

3.  Development, fabrication and testing of a check valve for use in the CCDR.  Requirements:  Passive – no electric or mechanical actuation  Operate at low temperatures (~1.8 K) with a mixture of He3-He4.  Seal at low back pressures (~3psi)  Negligible cracking pressure required to open Objectives

4. Check Valve Teflon seat reed check valve currently being refined and tested.