Caltech Optical Observatories Cahill Reference TWiki
Cahill Center for Astronomy and Astrophysics
General Instrumentation Meetings and Workshops
COO Lunch Time talks
12:30pm Wednesdays. See links above for details.
July 19 |
Pavan Bilgi |
Concurrent Clocking |
Pavan shows off a magic trick that makes most of the parallel transfer overhead disappear and reveals his next trick which will be to make charge traps disappear. |
July 26 |
Michael Feeney |
JT Cooler Survival Guide |
Michael tells how we escape from the grips of Polycold, an unreliable and expensive supplier, by developing in-house capability to diagnose and fix Cryotiger problems, find alternate sources, and refurbish used parts. |
Aug 2 |
Delacroix |
ZTF Window Supports 2 Tons |
The optical design wants the window to be thinner, but if it fails it kills the instrument and we are all going to be unemployed. Come find out how we achieved adequate safety margin for this brittle component, that has to support 2 tons of atmosphere. |
Aug 9 |
Smith and Kaye |
Waveform Definition Language |
We have a powerful new tool, a Waveform Compiler that interprets timing rules written in any order the user sees fit It configures the controller to make those waveforms happen, or plots them on a screen in a matter of seconds. At the same time the tool keeps the host software informed so detector engineer has a single point of control. |
Aug 16 |
Smith |
ZTF window Heater |
Thermal modelling shows that ZTF window will frost up. Come hear about how our AR coating provides >30W of make up heat. We'll also look at some other radiative transport issues for ZTF, such as whether the schmidt corrector will ever fog up? |
Aug 23 |
Steve Kaye |
Optmizing the ZTF pixel timing |
Squeezing the most out of the pixel time to maximize noise averaging at 1 MHz pixel rate, or to go even faster. |
Aug 30 |
Roger Smith |
Vacuum Advice |
What's important? What's not? How much to pump and how seldom. Initial cleaning and baking. Use a leak detector as your pumping station, but don't do stupid stuff. Cold traps. Underlying physics. Vital roles of getters and desiccants. Gauge types and ion pumps. How your cooling system affects all this. |
Proposed additions:
TBD |
TBD |
Focal Surface Metrology with On Sky Imaging |
Deviations of ZTF CCDs from the spherical focal surface delivered by the 48" schmidt have been measured using classic through-focus scans and extra-focal image analysis. Both methods survive testing with elaborate artifical data incorporating aberrations, diffraction, beam obstructions and vignetting by primary. Results differ somewhat but both report similiar unexplained curvature. Bring your ideas. |
TBD |
Feeney (TBC) |
Liquid cooling system design |
How to keep surface temperature of electronics enclosures within < 1K of ambient to minimize seeing degradation. Thermal circuit diagrams, non-linearities. Heat exchangers. Heat transport within enclosures. How much insulation? |
TBD |
Porter (TBC) |
Robotic filter exchanger |
Our first experience using and inducstrial robot in an astronomical instrument. Latches for secure hand off. Programming tasks and validation methods. |
Suggestions for talks? ...contact Roger Smith,
rsmith@astro.caltech.edu
Universities Space Research Association