====== Telecon 20180314 ======

Attending:Brian, Roger, Toki, Shaul, Kris, Karl, Qi, Amy

Notes by : Qi

=== Agenda===

  * TeamX studies (next two weeks)
  * {{::cpv.pdf|Calibration and performance verification}}
  * [[TempStability20180314|Temperature Stability ]]
  * Latest focal plane, instrument alpha, beta, ADR location, GRASP . . .
    *  {{::focalplane_update_20180214.pdf|Focal plane slides}}
    * Adjusted system to alpha = 30, beta = 65. 
      * Changes made: {{::2satellite_changes_20180314.png?direct&100|satellite changes}}
    * GRASP status: {{::grasp_status_20180314.pdf|grasp slides}}

=== Note ===

  * TeamX
    * Next week: Instrument study
    * 2nd week: Mission study
    * The results will go to independent cost analyzer
    * TeamX team is tailoring slides; we have option to add a narrative document
    * Shaul will send note about existence of telecons after TeamX

  * CPV
    * For Mission study
    * Planck had this phase, we will have too; we need to include this phase in our timeline
    * Based on ‘Planck HFI Core Team’ et al. 2011
      * CPV = “6 weeks before first survey”
      * Last two weeks of data have been included into the “1st survey data”
      * Slide3, Planck CPV
      * Slide4, PICO; Shaul only spent a few minutes; we can and probably should add more items
      * Cosmic rays
        * "What would change given the possible measurements during CPV?""Nothing" except some characterizations
  * Temperature Stability
    * Roger and Shaul are communicating; the results will go to Cryogenic Design
    * Roger
      * T stability of focal plane
      * ADR, thus we should not assume same stability as Planck.
      * The concern is that the real numbers we use
        * Loop gain = 1000 from thesis, very high, Roger think L~10 is more reasonable.
        * Alpha is also too large by a factor of 10 or more.
        * Toki agrees with Roger. Alpha is about ~100.
      * For LiteBird, super relaxed, requirement For T stability is very low.
      * Shaul: LiteBird no ADR, we don’t know what it should be for continuous ADR.
      * Roger: 1%Single ADR would heat the focal plane.
      * Shaul: timescale matters. We can calibrate on dipole. If the fluctuation is fast, then it’s problematic. On spin-spin basis (~1min), we would have dipole calibration. Timescale is unknown for CADR.
      * LiteBird: single shot, not ADR. ADR had been discussed. **Toki is going to dig out more information.**
      * Shaul: we will get information from Toki aobut LiteBird.
      * Roger: by next week, If we have a figure from Toki on requirement, we can have a number, we can put a reqirement on the fridge. Temperature constrained within some range.We are looking for “changes in detector response over some timescales”.
      * Roger: if you cycle ADR, before next cycle, you can do calibration.
      * Amy: on one hand, amount of requirement on changing responsivity and time scales; use calculation to infer Bath stability and timescale; we don’t need to go into too much details at this stage. More importantly, Decal Panel, risky or not.
      * Shaul: have no idea wether this is an issue or not; we don’t know ADR, fluctuation and timescale. Goddard may care cost, then they give us amplitude and timescale. Shaul will follow up.
      * “Common modes”, If the two polarization go down and up together.
      * Shaul will write to Tom, and with information Toki will proved, we will see what we need.
      * Kris: since this is a study, other techonologies could be mentioned.
      * Shaul: we will say there are emerging technolgy that may end being competative.

  * Focal Plane Status(Karl)
    * Slide2: nominal focal plane
    * Slide3: along the scan direction
      * Questions: 1) slight wider, looks more wasted space; 2)Center: pink is high-frequency, needs to be in the contour; we can futz around to make it good.
    * Slide4: two cases comparison.
    * Amy: either should be fine. 
    * Slide5: bump bond; stack multiple TDM chips below wafer.

  * GRASP:
    * Shaul: we understand now, working on slides.