2nCor Equipment
Detectors
PMTs
http://www.hamamatsu.com/resources/pdf/etd/R580_TPMH1100E.pdf
Scintillators
e+e- spectrometer
DAQ electronics
Signal Processing
Discriminator
CAEN N841
The pulse forming stage of the discriminator produces an output pulse whose width is adjustable in a range from 5 ns to 40 ns. Each channel can work both in Updating and Non-Updating mode according to on-board jumpers position. The discriminator thresholds are individually settable in a range from -1 mV to -255 mV (1 mV step), via an 8-bit DAC. The minimum detectable signal is -5 mV. The back panel houses VETO and TEST inputs, the OR output and the Current Sum output, which generates a current proportional to the input multiplicity, i. e. to the number of channels over threshold, at a rate of -1.0 mA per hit (-50 mV per hit into a 50 Ohm load) ±20%.
| LED output pulse width [arb. units] | Pulse width seen by the oscscope [ns] |
| 10 | 6.3 |
NIM-ECL converter
Phillips Model 726
TDC
Detector name convention
- BLUT = Beam Left Upstream Top pmt
3/19/15
- TDC channel Map (Thursday)
| Detector | Angle | TDC channel | NIM-ECL channel | Patch Pannel # | ROOT vaiable |
| BLUT | 135 | TDC 16 | in B ch 0 | 223A6 | evt.TDC[16] |
| BLUB | 135 | TDC 17 | in B ch 1 | 223A7 | evt.TDC[17] |
| BRT | 270 | TDC 24 | in A ch 0 | 223A14 | evt.TDC[24] |
| BRB | 270 | TDC 25 | in A ch 1 | 223A15 | evt.TDC[25] |
| BLDT | 45 | TDC 26 | in A ch 2 | 223A16 | evt.TDC[26] |
| BLDB | 45 | TDC 27 | in A ch 3 | 223A17 | evt.TDC[27] |
| Trig Delay | TDC 30 | in A ch 6 | evt.TDC[30] | ||
| Photon flux monitor | 90 | TDC 29 | in A ch 5 | 223A10 | evt.TDC[29] |
3/24/15
- TDC channel Map 3/24/15
| Detector | Angle | TDC channel | LED channel | NIM-ECL channel | Patch Pannel # | ROOT vaiable |
| 1 top (BRT) | 270 | 24 | 0 | in A ch 0 | 223A5 | evt.TDC[24] |
| 1 bottom (BRB) | 270 | 25 | 1 | in A ch 1 | 223A6 | evt.TDC[25] |
| 2 top BLDT | 45 | 16 | 2 | in B ch 0 | 223A7 | evt.TDC[16] |
| 2 bottom BLDB | 45 | 17 | 3 | in B ch 1 | 223A8 | evt.TDC[17] |
| 3 top | 60 | 26 | 4 | in A ch 2 | 223A9 | evt.TDC[26] |
| 3 bottom | 60 | 27 | 5 | in A ch 3 | 223A10 | evt.TDC[27] |
| 4 top BLUT | 135 | 18 | 6 | in B ch 2 | 223A11 | evt.TDC[18] |
| 4 bottom BLUB | 135 | 19 | 7 | in B ch 3 | 223A12 | evt.TDC[19] |
| 5 upstream | 135 | 20 | 10 | in B ch 4 | 223A15 | evt.TDC[20] |
| 5 downstream | 135 | 21 | 11 | in B ch 5 | 223A16 | evt.TDC[21] |
| 6 upstream | 135 | 30 | 12 | in A ch 6 | 223A17 | evt.TDC[30] |
| 6 downstream | 135 | 31 | 13 | in A ch 7 | 223A18 | evt.TDC[31] |
| e+ spect | 29 | 9 | in A ch 5 | 223A14 | evt.TDC[29] | |
| Trig Delay | 22 | 14 | in B ch 6 | evt.TDC[22] |
03/25/15
Wiring Work
- 3/25/2015
- Sean and Glen examined all of the signals from detectors 1 through 6
- We used the signal from the LEMO cables that go directly into the discriminator
- We also used the scope's Acquire->Average option and set the average to 512; This allowed for a more reliable comparison between signals
- Note that the threshold can be adjusted and that the average will be biased toward smaller pulse heights if there is a lot of noise
- Found an RG-62 cable connected between the bottom PMT of Det 3 and the patch panel A10
- Replaced with RG-58 cable
- A10 cable also found to be RG-58 from the experiment room to the counting room; Signal on 3B was degraded in the control room
- Changed to A19 (RG-223 the whole length) and the signal looked similar to the others
- Found that detector 5 top and bottom both were small and have the ~12 ns ringing
- Increased voltage to 1500V
- The non-extending gates from the discriminator will help with this
- Recommend a gate width of 20 to 25 ns from the discriminator to eliminate double pulsing from ringing on Det 5
- Should not matter for other detectors
- Will also not affect high energy neutrons since 6 MeV neutrons are 30 ns ToF at 1 meter
- When testing was complete, verified that all cables are associated with the appropriate detector
- Top/Bottom, Upstream/Downstream should not have been reversed for any detectors in the process but that has not been confirmed; this should be correctable in software
ADC
Software
Ntuple maker
To make the Tree containing the TDC, QDC, and PDC data run the following command
source ~/CODA/setup
/home/daq/CODA/CODAreader/ROOT_V5.30/v775v792v785/evio2nt -fr8735.dat >/dev/null
rename the output file to a root file
mv r8735 r8735.root
root -l r8735.root
to draw a histogram for TDC channel 16
DAQ->Draw("evt.TDC[17]>>(4096,0,4096)");