Overview

There will be roughly 6 weeks of time between the end of iPTF and the start of ZTF that will allow us to bring SEDM back to CalTech and perform some mechanical, electrical, and perhaps optical improvements to SEDM. Reston Nash will be the mechanical lead for these improvements. We are currently developing a plan and hope to order all parts and supplies by the end of February. Below are items we are considering for the engineering time. Our final plan will refine this list and prioritize the items. The list below is not in priority order.

Items Under Consideration for the 2017 SEDM Engineering time

1. Improve par-focality of IFU and RC.
2. Find the source of the low blue throughput
   1. Perform experiments to determine source of low blue throughput.
   2. Could be due to scattered light?
      1. Could be solved by baffling?
         1. Install better baffles
      2. Could be solved by better alignment?
         1. Improve optical alignment
   3. Could be due to optics
      1. Order higher blue throughput optics
3. Replace finite-lifetime parts:
   1. 2 shutters and common controller: RC and IFU
   2. IFU focus stage and controller
   3. USB to fiber interface
   4. Computer (we have two, but only one is configured to run SEDM)
   5. Hoses and internal cooling components
4. Improve reliability of power distribution with UPS, or power conditioner(s)
5. Install clamps on IFU camera barrel (already installed on lenslet array optics barrel)
   1. Test if clamps are causing any image degradation
6. Re-design enclosure to be smaller and sealable
7. Move electronics outside enclosure
8. Install active spring for IFU focus to apply positive pressure on stage
9. Semi-kinematic mounts for Detector heads to allow ease of installation
10. Improve baffling
11. Install order-blocking filter to remove blue scattered light below ~400 nm
12. Install correctly coated expander lens
13. Non-intrusive dust removal (no solvents, just air)

-- DonNeill - 07 Dec 2016