LBNL-2020: Cold Optics

Charge

With CD-1 coming up roughly one year from now we have to move to technology selection in the next half year. To meet this need we will have to have a review midyear. This session represents a first step toward this review where we will assess the technological performance and our ability to manufacture the required optical elements.

• discuss the LAT and SAT needs for cold optics (performance and production requirements of the LAT and SAT options)
  • metal mesh filters
  • alumina filters and lenses
  • silicon lenses
  • other filters
  • HWP (optional)
• describe the currently demonstrated status of the required technologies to meet both the technical and production needs.
  • Is there an existing supply path? If not how do we address that risk?
  • Discuss any risks to production (e.g., is the alumina or other material supplies secure?)
• What is the development path? Will it be done by CD-1 or require post CD-1 work?
  • Summarize/update technical risks, R&D / simulation needs to retire those risks.

Agenda

Call in via Zoom: https://lbnl.zoom.us/j/189656154

Notes can be found here: https://docs.google.com/document/d/1win-exuExCS06CCN4JrH5tErXSio8yX50OJ_v_EUeCE/edit

• Overview of LAT cold optics needs File:Receiver optics numerology 20200305.pdf (Niemack)
• Overview of SAT cold optics needs (Kusaka)
• filters (Tucker) File:Optical filters for S4 April 2020.pdf
• silicon lenses (Golec) File:Silicon Lens AR Production CMBS4.pdf
• alumina optics (mention if these coatings are applicable to sapphire)
  • laminate (Vieira)
  • B/K laminated coatings for alumina (Marion) File:20200401 CMBS4 epoxy coatings Dierickx.pdf
  • epoxy (Hill)
  • thermal spray (Lee) https://www.dropbox.com/s/qstwm77yt2lt51u/Thermal_Spray_ARC_Lee_Jeong.pdf?dl=0
  • laser (Tomo)
  • metamaterail (Golec) File:Alumina mmAR s4 lbnl2020.pdf
• Production and acquisition of alumina lenses
  • Akito (w/ input from Masaya Hasegawa @ KEK, Japan)
    • Vendor: NTK technologies (formerly known as Ceratec Inc.) http://www.ntktech.com/
    • Material: 99.5% LD (low loss type: https://www.ceratech.co.jp/en/product/material/alumina/a9951ld/)
    • Shaping: shape and bake (no machining after baking), desired accuracy achieved (~+-25um across ~60cm lens), flange and holes can also be done.
    • Precedent: PB2a lenses and filters, SO SAT and LATR filters.
  • B/K Lenses (Marion, Ben S.) File:20200401 CMBS4 Lenses Dierickx