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SB Status Update. Jason for the SB Tent Crew. Sept 26, 2006. Noise [(S 8 +S 9 +S 10 )/3 – S 0 ]. HBD west (on the bench). HBD west (on the bench). Prototype in the hall, 8-1-06 (thanks Itzhak!). HBD west (on the bench). Gain Curves. New method for fitting gain curves
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SB Status Update Jason for the SB Tent Crew Sept 26, 2006
Noise [(S8+S9+S10)/3 – S0] HBD west (on the bench) HBD west (on the bench) Prototype in the hall, 8-1-06 (thanks Itzhak!) HBD west (on the bench)
Gain Curves • New method for fitting gain curves • in regions of large gain drop, set errors to be large. • include the last point of the curve when fitting the time constant. • adjust by hand, if necessary. • Fits look much better now. • Time constants typically ~30 min (up to nearly 2 hrs)
Gain Maps noise • The RMS of the gain maps have some variation from stack to stack. • ~20% • ~5% • Possibly dependant on orientation of scope during data-taking. • Very recently discovered that this reduces the noise… BAD!! GOOD!!
Flashing the Gain Test Box • Sasha brought two 250nm LEDs. • Circuit has been built to power them. • Empty port on top of gain test box already has a MgFl adapter. • Ready to try to flash a GEM stack (time permitting).
Present Status • 8 stacks are installed. • Evaporation on final 4 GEMs is finished, will QE test and transport this afternoon. • Hopefully, all stacks will be installed by the end of the week. • No real hiccups so far!!!
New Idea • Heat HBD east outside of the glovebox (under flow) • Heat the glovebox atmosphere with the vessel open! • Glovebox is the cleanest environment we have. • ability to heat all the “nooks and crannies” inside the vessel. • Remember… • HBD west had ~1 month in GB at ~37 C. • HBD east has had ~2 weeks in GB at ~32 C. • for the west, GB had achieved ~2ppm, • presently, we’re at ~5ppm. • We probably should heat HBD east for a bit inside the glovebox. • This can be accomplished by simply heating the gas input lines (something we already have experience at)! • ps. Check out the new hyperlon gloves!!
Conclusions • non-Gaussian tails of the noise distribution are gone (HBD west). • Probability to fire on the noise: • <1% at 3σ • <5% at 2σ • All noise of HBD west on the bench is tiny compared to the prototype in the hall. • Gain curves are being fit with more accuracy (checked manually). • Gain maps in the database have been updated. • Ready to flash a GEM stack in the gain test box (time permitting). • Production is becoming very routine (in a good way!!), like clockwork! • We should heat the GB atmosphere.