Transcript 2013-01-04, Dan Peterson some comments on December 2012 xBSM data

2013-01-04, Dan Peterson
some comments on December 2012 xBSM data
The day-to-day measurements of image area are not consistent.
Multiple measurements total image area vs. pinhole size (TASGAP)
are inconsistent at the level of 20%, and sometimes 50%.
The large changes are possibly due to timing and/or orbit.
There was no TASGAP slip in D-line as reported 2012-12-07, no slip in zero point.)
Filter studies, taken in the same day/hour, can be compared with confidence.
filter scans: PRELIMINARY comparison of data with model
DATA was taken at 3 energies: 1.8, 2.085,2.3 GeV ;
with 4 filter conditions : none, diamond, aluminum, molybdenum
All 12 conditions were successful in the D-line;
only 2.085 GeV was repeated in the C-line.
I use the relative transmissions of the filters, normalized to “no filter” at each energy.
A subset of these conditions were measured in the C-line in April 2012.
The model has been tuned using the 2.085 GeV Diamond filter transmission.
The new data agrees on this point.
The model is used to predict the relative transmission.
Revised model has 10 energy bins (up from 7)
and 128 12.5 micron pixels (up from 64 25.0 micron pixels)
Some errors were uncovered.
The energy exponent was retuned to provide 0.52 transmission for 2.085 diamond.
The exponent is changed to 2.15 (from 2.31).
MODEL
For comparison, the December 2012 data is repeated here.
Note that the model is, in general, low for 1.8 GeV, and high for Aluminum.
DATA
The comparison of the model to the data is expressed as
(model) – (DATA)
-------------------------(DATA)
Again,
note that the model is, in general, low for 1.8 GeV, and high for Aluminum.
The high transmission for aluminum, in the model, indicates that the x-ray energy
spectrum must be decreased where there is aluminum transmission.
The low transmission for molybdenum, in the model, indicates that the x-ray energy
spectrum must be increased at low energy.