1. News from B180: DC-DC Stavelet with HV MUX One hybrid shows ~20ENC extra noise, others much the same. Not yet understood - investigations continue Carlos Garcia Argos Giulio Villani Matt Warren Todd Huffman Peter Phillips 1

2. News from B180: DC-DC Stavelet with HV MUX A little more variation – nothing too significant 2 Carlos Garcia Argos Giulio Villani Matt Warren Todd Huffman Peter Phillips

3. News from RAL: New SP Stavelet EoS mounted BCC terminations removed / changed to 56R Several flavours of “PPB” in hand – CofH PPB (with components) – CofM PPB (no components) – CofM STAR PPB replacement (filtering but no shunts) Stavelet now aligned under module placement system – Alignment took a long time, see over Bottom line: – Ready and waiting for modules 3

4. 4 Aluminium Edge Gold Plated Copper Edge Lacking kaptons that are ‘correctly placed’ or of the correct size, there is simply no way to accurately position modules onto the stave(let). – Need to build to gaps between the shield pads Assembly optics designed to pick up small fiducials with high accuracy – Not good with “long” straight edges, especially if they’re not actually straight On the current stavelet kapton the edges of the etched aluminium are not suitable for alignment purposes – Gold plated copper layer has good detail, but that’s the wrong layer Future stave(let)s need one or more fiducials to be added. A survey can then be made once with more appropriate optics (eg large area smartscope) and thereafter the build may proceed wrt the fiducials. – Unless it’s possible to add fiducials on the Aluminium layer? Lacking kaptons that are ‘correctly placed’ or of the correct size, there is simply no way to accurately position modules onto the stave(let). – Need to build to gaps between the shield pads Assembly optics designed to pick up small fiducials with high accuracy – Not good with “long” straight edges, especially if they’re not actually straight On the current stavelet kapton the edges of the etched aluminium are not suitable for alignment purposes – Gold plated copper layer has good detail, but that’s the wrong layer Future stave(let)s need one or more fiducials to be added. A survey can then be made once with more appropriate optics (eg large area smartscope) and thereafter the build may proceed wrt the fiducials. – Unless it’s possible to add fiducials on the Aluminium layer?

5. Preparations for the (DC-DC) Stave: Build options Plan to use new assembly system – Four module placement bridges 90% complete – Expect to be ready in a few weeks. Need engineering drawing of stave including all PCBs – Need mechanical stave(let) for trials Request >~5cm pipe external to stave – Shall investigate temporary pipe extension to more robust pressure connector Shall stavelet have continuity test before it arrives here? 5

6. Preparations for the (DC-DC) Stave: Service options Low Voltage 1.We have one TTi TSX1820P PSU. We could buy two more and power each segment separately 2.We have one EA PSU rated at 100A. We could use this via some kind of current monitor / fuse panel akin to the way Geneva power the supermodule. High Voltage 1.We could use 12 channels of SCTHV, one per module 2.We could use (say) 3 channels of SCTHV, each one fed to four modules (= one DC-DC segment) though a multiplexer. – Both options would require a simple PCB or equivalent to be made, but for the 12 channel case we also need more cables. DCS – Do we need additional T monitoring? The stave must run cold, and may do so before all modules have been fitted Propose to add “one wire” T sensors at a few locations along the power tape – Humidity Monitoring Matt is working on firmware to read SHT71 sensors through HSIO. 6

7. Preparations for the (DC-DC) Stave: Service options Environmental Enclosure – Plastic covers with o-ring seals built into assembly frame? CO 2 Cooling – Blow off cooling system exists at RAL will need to be relocated – Outdoor “Gas Hut” on order to be fitted next month – Further investigation & adaptation may be needed Scales to weigh bottles, readable from inside? Humidity and pressure Interlocks? – Plan to have internal meeting within the next few weeks 7

8. Tandem DC-DC Latest provisional layout from Georges and Isaac Bond pads aligned to power bus Star point is now on the PCB Area in which one wire T sensors could be mounted 8