This is a short description of a new segmented aperture scintillators detector for the Møller detector.
New aperture detector consists of 4 segments each (left and right). The segments have a different length and width.
The longest one is located outside of the detector center. Other three segments are located on the site closer to
the detector center. The sketches of the aperture detector are shown here (pdf format)
and here (pdf format) . Photo of the aperture detector in assembly is shown
here . The Hamamatsu R4124
PMTs are used for all 8 channels of the aperture detector.
Bellow is a numbering of the aperture scintillator segments:
Below is the aperture scintillators connection to the signal panel in the Møller old DAQ rack.
| Signal Name | Cable # | Panel Connector # |
| Ap_Left_#1 | 033 | 33 |
| Ap_Left_#2 | 034 | 34 |
| Ap_Left_#3 | 035 | 35 |
| Ap_Left_#4 | 036 | 36 |
| Ap_Left_#5 | 037 | 37 |
| Ap_Left_#6 | 038 | 38 |
| Ap_Left_#7 | 039 | 39 |
| Ap_Left_#8 | 040 | 41 |
High voltage cables for aperture scintillators:
| Signal Name | Cable # |
| Ap_Left_#1 | 013 |
| Ap_Left_#2 | 014 |
| Ap_Left_#3 | 015 |
| Ap_Left_#4 | 016 |
| Ap_Left_#5 | 017 |
| Ap_Left_#6 | 018 |
| Ap_Left_#7 | 019 |
| Ap_Left_#8 | 020 |
High voltage channels (slot #6 ) for aperture scintillators:
| Signal Name | HV channel # |
| Ap_Left_#1 | 00 |
| Ap_Left_#2 | 01 |
| Ap_Left_#3 | 02 |
| Ap_Left_#4 | 03 |
| Ap_Left_#5 | 04 |
| Ap_Left_#6 | 05 |
| Ap_Left_#7 | 06 |
| Ap_Left_#8 | 07 |
To control HV settings for aperture (slot #6) and calorimeter(slot #5)
channels one should login to HV mainframe using command:
> telnet hatsv5 2003
and then start 'vt100' program.
Aperture scint. signals from panel connectors going to the amplifier PS776 (delay is 4ns): panel connectors #33-#40 to PS776 channels 1-8. From the outputs (#1-8) of this amplifier signals are connected to inputs of the FADC. The delay between aperture scintillators and calorimeter signals on the panel connectors is about ~10-12ns (aperture scint. signal appears early).
For old DAQ we take signals also from output of the amplifier and connecting its to the discrimintor PS706 with threshold presets to -200mV and then send its to OR module PS740 to have two sums of four left and four right aperture signals, that we can use without of modification old DAQ.
