|
|
| (2 intermediate revisions by the same user not shown) |
| Line 1: |
Line 1: |
| − | The Q-Weak Amplifier Discriminator, termed as QWAD has 48 channels on each electronic board. We would be using 2 QWAD boards per plane. One QWAD will process the signal from all odd strips of the detector, while another processing the signals from all even strips.
| + | #REDIRECT[[Electron_Detector#e-Detector_Motion_System]] |
| − | | |
| − | Though functionally the board is capable of operation in both positive as well as negative polarity. We shall be using it in negative polarity with the jumpers on the inner side of each channel ([[Media:QWAD.png| diagram elaborating jumper placement]])
| |
| − | | |
| − | The QWAD (version-2) being used requires +5,-5 and two GND connections for its power supply. We are using two Agilent E3633A LV [[http://hallcweb.jlab.org/polwiki/index.php/Low_Voltage_Power_supply_for_QWAD power supply]] to provide the same. The QWAD boards would be attached to the vacuum - can in the tunnel whereas the power supply needs to be behind the Green Wall (2nd rack allocated), which adds a long cable of ~120 feet between the power supply and the consumer QWAD boards. We are using a 5 conductor 12 AWG cable for carrying 8 x 1.6A (~13A) from one power supply unit delivering +5V and 8 x 0.37A (~3A) from another unit delivering -5V. We use a 22 AWG cable for sensing the voltage at the load. A terminal block is used to send out this voltage to all of the 8 QWAD boards.
| |
| − | | |
| − | | |
| − | == Current Status of QWAD version-2 boards ==
| |
| − | We have received 8 QWAD boards on-site after being mended at TRIUMF.
| |
| − | | |
| − | * QWAD3: all channels giving digital output, first 11 channels were particularly noisy [https://qweak.jlab.org/elog/Electron+Detector/81]
| |
| − | * QWAD4: Tested and found quite clean, the most noisy channel is only 400Hz.
| |
| − | * QWAD5: ''not tested yet''
| |
| − | * QWAD6: ch#1,38 have no digital output, noise rate as seen with and without calibration input was a maximum of 2kHz.
| |
| − | * QWAD7: ''not tested yet''
| |
| − | * QWAD8: all channels giving digital output, noise rate as seen with and without calibration input was a maximum of 2kHz.
| |
| − | * QWAD10: ch# 7,8,11,34,38,45 either do not have a digital output or has a flaky output.
| |
| − | * QWAD11: ''not tested yet''
| |
