Figure 1 shows the configuration of the cold stages. The first two stages on the Stirling cooler reach 170K and 20K while the third Joule-Thomson stage allows the base temperature of 4.2K to be achieved. The third stage is attached to the others via a 3D printed mount, giving structural stability with a low thermal conductance. A JT by-pass system diverts gas flow past the third (JT) heat exchanger and the orifice. This acts as a thermal switch thermally connecting the final stage to the coldest stage of the Stirling pre-cooler. When the temperature of the final stage is close to that of the pre-cooler the by-pass systems is deactivated and the flow then goes through the orifice and JT cooling starts. Radiation shields attached to the two stages of the Stirling cooler reduce the heat load to the final stage. The radiation shields are covered with Multi Layer Insulation further reducing the heat load. The long life of these devices comes from the use of flexure bearing technology which are operated well within the fatigue failure limit of the material. The compressors are reciprocating and the flexure bearings are used to support the pistons. The pistons are non-contacting and operated at 30-50Hz which limits the "DC" gas leakage. The gas in the JT system is circulated through a gas panel which contains pressure transducers, a mass flow meter and a getter. The getter removes contaminants from the gas which might block the orifice on the JT stage. Additional filters on each of the cold stages also help to clean the gas prior to expansion. These measures are necessary as the orifice size is only approximately 12 microns. The mechanisms have undergone mechanical tests appropriate for an Ariane 5 launch. The cooler provides around 6mW of cooling power at 4.2K which is appropriate for the type of work on SNPDS's. Brief Notes on a Meeting to Discuss ongoing Work at Birmingham University on Catalysts for Ortho Para Hydrogen Conversion Present (with contact details) Lynne Macaskie, Birmingham, Lynne Macaskie Iryna Mikheenko, Birmingham, I.MIKHEENKO@bham.ac.uk Tom Bradshaw, RAL Cryogenics, Tom.Bradshaw@stfc.ac.uk Beth Evans, RAL ISIS, Beth.Evans@stfc.ac.uk Stephen Gallimore, RAL ISIS, Stephen.Gallimore@stfc.ac.uk Josef Boehm, RAL Cryogenics, Josef.Boehm@stfc.ac.uk David Jenkins, RAL ISIS, David.Jenkins@stfc.ac.uk cc: John Vandore Iryna and Lynne described the work at Birmingham University on catalysts based around bacteria that take in metals on the surface of the cell due to the action of enzymes. Discussion: ISIS are interested in measuring the ortho/para hydrogen ration in the moderator but are limited in the measurement techniques. Raman spectroscopy may be a solution.Currently working with the group at Dresden. Would this type of catalyst be a competitor to the currently available (and cheap) ones such as Fe2O3, Ionex, Oxysorb etc..? Possibilities of getting a student to look at measurement techniques and effectiveness of various catalysts? Quantities needed would be around 10g for a decent measurement. ISIS will pose the questions that need answering for their application. Any ESS interests? BU should present a poster (at least) at the Cryogenic Cluster Day (JV) SG to foward coordinates of the RCAH catalyst group (done) Tom Bradshaw Anete Ashton Conference Commissioning Editor IOP Conference Series Temple Circus, Temple Way Bristol, BS1 6HG Direct line +44 (0) 117 930 1280 Mobile +44 (0) 7803 248 290 lf107@le.ac.uk 0116 229 7681 Matt, Martin, Chris, Quantuum Hub I analysed the results from last week and these are in the usual result folder. I compared data with the last three runs to see if there is any degradation. My feeling is that we are just on the cusp of getting cooling. I looked at the cooling loop: a) Half of the metal clamps have been removed and these are being re-made in GRP to that pattern. Hopefully these will be finished today. b) The copper clamp on the displacer was only held on by on M3 cap head. When I investigated this with Chris the situation looked even worse. The screws were supposed to go straight through the copper into the Aluminium base. In fact there is only thread on the central screw and that is dodgy with only a few threads holding on. I took the heat exchanger off, cleaned it and Stycasted it neatly in position secured with the central screw. I have installed the scope card - the (slightly wrong) cables came today and I plugged all in and ran the system without problem. The scope card is on the screen at the moment but pinned to the start bar if you lose it. The configuration is "as you left it" so should work straight off. Chris is ordering what will hopefully be the correct ones... Tom2 has installed latest Labview (2015) and pinned the programs to the taskbar. Heat Exchanger I have come up with a better configuration for the spiral heat exchanger. The sketches are on my desk. I could use a bit of Sean's time. If he has nothing to do you could start him on that? Chris knows what the aim is. The files are in: O:\01 Projects\03 Magnets & Facilities Programme\2015-10 MgB2 Cooling\03 Design\2016-09 Design The spiral file is "Sprail HE 04.par" (not my spelling) Castaway Neil Bowles would like to come here Tuesday afternoon to discuss, see the lab etc... - you are on copy. CFI I have filled in the response form from the review. Martin you need to look at that, revise and action. Regards Tom