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| + | === Notes === | ||
| + | * SPIE | ||
| + | * in June, mostly technical | ||
| + | * Apr 9, deadline for finalizing the author list and material | ||
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| + | * TeamX meeting | ||
| + | * 2nd Instrument meeting; Mission meeting | ||
| + | * Overall cost is the the most important product | ||
| + | * no significant revelation | ||
| + | * Focal plane | ||
| + | * converged to one configuration; | ||
| + | * the other two, we have to change the optical design, to accommodate with high frequency | ||
| + | * this focal plane has largest number of detectors; the difference compared to other two is very small though. | ||
| + | |||
| + | * Noise budget | ||
| + | * V3.2: very little change from V3.1; noise 0.63 uK arcmin before, now 0.61 uK arcmin | ||
| + | * compare values with CORE and LiteBird calculation, | ||
| + | * we are using two independent codes to calculate. Karl at UMN; Roger at JPL. Agree within 5%, slightly difference. Reasonable confidence. | ||
| + | * various assumptions | ||
| + | * to what extend our assumptions agree with other experiments | ||
| + | * in some bands, noise lower than LIteBird, some bands higher than LiteBird. | ||
| + | * everything seems consistent, no major change | ||
| + | * Psat, safety factor of 2, we haven chosen a factor of 2, it’s used by JPL folks, also by SPIDER AND KECK. We thought it’s reasonable. | ||
| + | * Quantitative calculations will be done by next week: what T of elements (mirros) could bring us to a factor of 2 | ||
| + | * Efficiency | ||
| + | * It varies between the bands | ||
| + | * Detector: lenselet + antenna + bolo, 70% | ||
| + | * Edge Taper: center 10 db, lower band and higher band have different values; low, center, high: 70%, 90%, 99%. | ||
| + | * End to end, 50-70% | ||
| + | * Optical efficiency can mess up the estimate on safety factor | ||
| + | * Emissivity | ||
| + | * We are using measured emissivity from Planck. We already know, for highest bands, we may need to change to be more conservative | ||
| + | |||
| + | * Margins | ||
| + | * Space Mission, “current best estimate”, | ||
| + | * What margin is the judge, successful or not. | ||
| + | * Two paths: | ||
| + | * 1. start with assumptions | ||
| + | * each one assumption | ||
| + | * "worst case" | ||
| + | * 2. We can propagate backs from sigma_r 2*10^-5. | ||
| + | * 3. maybe a 3rd one, some factors on NET. | ||
| + | * Kris: instrument is one thing, how to get data to science is another | ||
| + | * Raphael used mapping speed, assuming delensing on our own resolution. 1*10^-4 is the limit that Shaul said in AAS, which has margins from calculated value 2*10^-5. | ||
| + | * It's not a trivial calculation | ||
| + | * LiteBird | ||
| + | * does have margins | ||
| + | * "large sections", | ||
| + | * quote r with margin in it | ||
| + | * nominal performance and worst performance. Give both to science team. Worst case did not give too much science. Lately, increase number of detectors to improve “worst case” | ||
| + | * Shaul is going to check with Planck team | ||
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| + | * Workshop | ||
| + | * suggestions: | ||
| + | * Kris: 1) without modulator 2) arguments on margins | ||
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