Flight Calibration and Weighing the Instrument: November 30, 2012

With the Hang Test completed, Friday we got to work on our to-do lists before flight. JohnE, Bob, and I worked on where we wanted to set high voltages during flight. I had our Scintillator Detectors (again, I'll try and have an about-the-instrument post up soon since our official website is down) and had to figure out exactly how we wanted to calibrate the instrument. Particles will create a different signal based on how heavy they are (heavy=higher signal), what angle they come in at (straight down=lower signal, 45 degrees=much higher signal), how much energy they have, and how far away from our Photomultiplier Tubes (PMTs) they are. The way I ended up setting things up, a heavy (Neodymium, atomic number Z = 60) particle near a tube at 45 degrees theoretically gives us a signal of 52,050 channels, while the lightest particle we're looking at, a Neon ion coming in vertically far away from the tube gives us a signal of just 99. This gives us enough range that we should hopefully be able to see everything we want to see with our detectors. Bob and JohnE did similar work with the Hodoscope and Cherenkov detectors, respectively.

From this, we'll get an idea of where we'll set our high voltages, which we plan to do on Saturday. There are a few other things we want to get up and running, but in general it looks good for a flight at the first opportunity sometime next week.

BLAST spent most of the day outside doing more testing, so we had some space inside. In the afternoon, some CSBF people came over with a scale that hooks up to the crane and weighed the payload. The entire thing, including the instrument, gondola, SIP and antenna boom, but not counting our flight straps, came in at 4465 lbs. This is around where we expected to be, since our goal was to weigh around 4000 lbs for our science weight with a few hundred pounds of weight from CSBF's equipment. It should put us in a good position for the balloon we want to be on for launch day.