Minutes of 7/25/00 lab meeting

Meeting Agenda and Minutes are posted at: 
http://scipp.ucsc.edu/groups/glast/meeting/glab_meeting/

Wilko said that we have a second VME crate and TEM board to setup a PC
based readout 
system.  He would like to consider using Linux instead of windows, but it
costs an extra $700 and 
may take longer to setup.  Wilko also described his studies of pickup on
the tower.  He is looking 
at the fast OR with a scope while sending signals to the front end.  The
data is confusing and some 
work needs to be done to isolate the pickup location between cables, TEM
board, repeater 
cards, etc.

Masa presented a plan for the single chip testing (this is a chip hooked
up to a ladder of "baby" 
detectors). The  things he wants to test are:
        -power consumption in quiet state, 
        -snap shots of pulse shapes (preamp out and shaper out)
                for 1 MIP signal
                for large signal (a couple of hundred MIPs)
        - amp. gain
                preamp and shaper by pico-probing at around 1 MIP
        - FastOR timing
                leading edge of FastOR from charge injection
        - ToT length at various chage injection
                for around 1 MIP
                for large signal
        - recovery time of a channel
        - saturation of ToT for large signal
        - noise measurement by threshold scan with charge injection
        - occupancy scan

Mat has the LabView program to control the environmental chamber working.
He can control 
basic chamber functions and set parameters for one cycle.  He is working
on an array type input 
for a more complicated sequence of temperatures, ramp rates, and dwell
times.

Hartmut summarized the state of thermal test data analysis by Colleen.
There is difficulty 
understanding measurements above room temperature since they never came to
equilibrium 
(thermal runaway).  The current vs. temperature curve looks like it
follows expected exponential 
until low temperature when the current increase presumably due to stress.

Gwelen explained that Kamal is working on understanding the DAQ for
reading out RTD 
temperature probes.  There are some software bugs and the temperature
resolution is not yet 
understood.  We would like to make it a priority to have this system
working for use on the 
environmental chamber.  There is also the possibility of buying identical
hardware so the chamber 
would have its own system.  It would be nice to buy an ADC with slightly
higher resolution to have 
the possibility of 0.1 degree resolution.

Hartmut said that a detector has been irradiated with 5Krad and needs I
measured and then 
annealing at 40 C for many cycles.  Danny is working on this, and
Alessandro is over-seeing the 
measurements.

AOB

Hartmut made a friend at NRL who want to do SEU tests on our chips.  He
suggested giving them 
the setup used for SEU tests in Japan to get them started. Masa will
request from Tsune to have 
the board returned.

The time for this meeting has been moved to 1:30 on Tuesdays so that Alec
can attend.

Action Items:
Wilko/Nick/Gloria - Get Windows based VME readout working
Masa - Ask Tsune to return the board 
Mat - Ask Sun Systems about N2 purge and user probe in environmental
chamber
Gwelen - e-mail Hytec to ask them to give Robert our power supply
Kamal - get temperature readout system working. understand resolution