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imagerteleconnotes20180509 [2018/05/09 13:34] kyoungimagerteleconnotes20180509 [2018/05/10 14:19] (current) wenxx181
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 ====== Telecon 20180509 ====== ====== Telecon 20180509 ======
  
-Attending: +Attending: Toki, Shaul, Karl, Qi
  
 Notes by : Qi Notes by : Qi
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   * Workshop Follow Up Items    * Workshop Follow Up Items 
-    * Focal plane mechanical model (SH + UMN)+    * Focal plane mechanical model (SH + UMN); 1/f; temperature stability; detailed cryogenic model;
     * Precession Speed (Kris, Jacques)     * Precession Speed (Kris, Jacques)
     * TDM/FDM noise comparisons (Karl, Roger)     * TDM/FDM noise comparisons (Karl, Roger)
       * Plots of ratio of FDM to TDM noise.  Ratios are NEP^2 (left) and NEP (right)       * Plots of ratio of FDM to TDM noise.  Ratios are NEP^2 (left) and NEP (right)
       * {{::tdm_fdm_ratios.png?direct&600| FDM/TDM noise}}       * {{::tdm_fdm_ratios.png?direct&600| FDM/TDM noise}}
-      * Largest difference is NEP_FDM NEP_TDM = 1.02.  Or ration of squares, (NEP_FDM NEP_TDM)^2 = 1.03+      * Largest difference is NEP_tot_FDM NEP_tot_TDM = 1.02.  Or ratio of squares, (NEP_tot_FDM NEP_tot_TDM)^2 = 1.03 
          
  
 === Notes === === Notes ===
 +
 +  * Workshop Follow Up Items 
 +    * issues of mechanical model: focal plane weight, needs to be revisited and a more realistic model in a few weeks. Heat sinks, mounts etc.
 +    * **Toki will provide PB focal plane module**
 +  * 1/f
 +    * a number of discussions need to be tighten together
 +    * temperature stability of ADR, Hannes asked to what extend spikes of T affect responsivity
 +    * we know the magnitude of T spikes; should be straightforward
 +    * we don’t have complete cryogenic model, temperature loading is **AI for Shaul and jPL**
 +  * Precession
 +    * Jacques proposed slow precession; because the scan by scan is closer together, you can make full sky; harder to make continuous map with fast precession
 +    * Kris prefers fast precesson
 +  * TDM and FDM
 +    * We have been assuming sensitivities on FDM coming up from Matt and Franky, but the baseline (physical layout) is TDM
 +    * Karl's investigation
 +      * most recent TDM number from Roger
 +      * photon and phonon calculations between Karl and Roger agree within 1%.
 +      * ratio of total NEP squared, largest 3%
 +      * basically FDM is higher by 2-3% level. 
 +    * Toki: readout noise is function of bolo normal resistance; TDM ~10 ohms, FDM ~1 ohm; TDM higher because it needs to compensate high current noise
 +    * **Conclusion: same. the numbers we had from FDM are fine.**
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imagerteleconnotes20180509.1525890871.txt.gz · Last modified: 2018/05/09 13:34 by kyoung