Qweak GEM installation log book

5/12/2010

Detector installation

The Qweak GEM detector has been installed in the doghouce in Hall-C and the HV was turned on. On the scope picture below is shown the GEM trigger out pulse, after it has been amplified and integrated with timing filter amplifier. The high voltage supply is placed in the doghouse with the other electronics.

Electronics

We have the NIM Bin with the following modules: Leading edge discriminator, timing filter amplifier(X2), Gumstix module.

Gas

The gas bottle filled with ArCO2 is placed outside the doghouse. We have two 90 ft shielded twisted ribbon cables next to region 1 area.

cables need to be routed about colimator 2.

5/13/2010

Met with Kelly Tremblay to discuss survey plans. Goal is to be ready for Qweak collaborators and survey crew to align detector on June 4. The "Fork" used to connect the GEM detector to the translator will be fiducialized for the laser survey system by mounting 4 targets on the fork. The request is to have the "Y" location surveyed in to 100 microns (this is essentially [math]\theta[/math]) . We desire the X-location to be surveyed within 250 microns. The Z - location beam upstream/downstream is the least critical.

DAQ computer name is : cdaql6

R1 ROC name : qwvme11

using the terminal server to login to the R1 ROC

telnet hctsv11 2008

Gumstix and I2C

Brad Sawatzky: Contact for ordering gas ionfrastructure (bubbles, hose , valves,...)

5/14/2010

Gumstix sees the network now. It will be known as qwgemgumstix and have the IP address 129.57.168.91

We may also use the terminal server to login via the Gumstix's serial port but you must be logged into cdaql6 (or a computer on the same network as cdaql6)

telnet hctsv11 2007

Runcontrol runs the cMsg server.

Gumstix contains cMsg client and subscribes to the Runcontrol cMsg server. once receiving message from ROC it then send out a message of the current thrshold value which the ROC has subscribed to . This tells the ROC to pulse again.

Carl Timmer has a sample code in C.

use Send and Get

ROC is a cMsg client as well

ROC spawns a task upon userGo and starts stepping through Discriminator setting task start a pulse and sleeps until a Mutext comes then it sends a cMsg to Gumstix

search jlab.org nameserver 129.57.32.100 nameserver 129.57.32.101 [cdaq@cdaql6 ~]$ nslookup cdaqfs Server: 129.57.32.100 Address: 129.57.32.100#53

Name: cdaqfs.jlab.org Address: 129.57.168.10

is go to the next threshold setting.