IAC 1-8-08

From New IAC Wiki
Jump to navigation Jump to search

Signal Cables

HV settings
Cable # Volts Desc
223A10 Metalica Sense Wire #4
223A11 Plsstica Sense Wire #4
223A12 1105 PMT Scintillator
223A13 1110 Middle Scintillator
223A14 1090 Last Scintillator (Veto)
223A15 V260 Scaler Input
223A16 V260 Scaler Input

Drift Chamber

90/10 ArCo2

Drift Chamber HV

HV settings
Cable # Volts Current (ma)
Sense 1456
Field 729
Guard 731

ADC Channel ID

ADC Channel IDs
ADC Channel Desc Patch Panel Channel
0 Metalica wire 1 1
1 Plastica wire 1 2
14 Front Scint 15
15 Back Scint 16
16 Veto Scint ribbon cable

ADC Peaks (RMS)
300 344 (16) 252 (34 -- dbl pk) ped ped
301 346 (18) 290 (17) ped ped
302 441 (8) + ped 253(8) + ped ped ped

Run 297:

First measurement with ADCs. Zero position (beam hitting trumpet).

Run 298:

Move Drift chamber 1 cm (-20,000 on axis 2, 0.4 [inches] left arrow on GUI) away from trumpet.

We had no PMT coincidences (OR was on).

This run should be ignored because table position meter ("Axis-3" MC 2000) was on and that caused noise on PMT signals.

Run 298:

Run 300.

gate width: 600ns.  PMT gains too low.  Timing is around 100 ns out of time. Plastica and Metalica look good.  

Run 301

Increase gate width to 1 us. PMTs still in the ADCs, but gains are too low. Longer gate width allows for complete integration of the wirechamber ADCs. Signals are better. Position at 1cm from trumpet of feedthrough. 2376 evts.

Front scint 1160
Middle scint 1100

=Run 302

Front scint 1220, Disc threshold 200 mV (Big paddle)
Middle scint 1175, Disc Threshold 51 mV rate is around 1 Hz.

Run 303

Increase current to 15 Hz

FastClear IN

Run 304

Increase current to 15 Hz

FastClear OUT

Run 305

Increase current to 15 Hz

FastClear In

Moved FastClear to 20 us from gate.

Run 306

Run 307

Everything ORed. Singles. Something wrong with the ADCs. Swap cables to ADC 7 and 8 (plastica and metalica)

Run 308

Plastica SW3 --> Ch. 7 (ADC6) Metalica SW4 Ch. 6 (ADC5) Plastica SW4 --> Ch. 8 (ADC7)

FastClear OUT.

Run 309

Metalica SW4: Ch. 7 (ADC 6)

Plastica SW4 Ch. 8 (ADC 7)

Has stuff in Chan. 8 and 7. Singles (ORed).

FastClear OUT

Run 310

FastClear IN.


Run 311

Swap polarity of FastClear. Singles.

Run 312

FastClear IN. Coincidences.

Stuff in Ch. 9 nothing in Ch. 8. nothing in Ch. 7

Run 313

gate width 600 ns FC in

Run 314

FC out

Run 315

HV: SW: +1500V GW: +750V, FW: -750V

Run 315

HV: SW: +1500V GW: +750V, FW: -750V

HV: SW: +1550V GW: +775V, FW: -775V No change in Ch 9. It does not change anything in the ADC.

HV: SW: +1500V GW: +750V, FW: -750V

Run 317

Not gated right. Wchmbr pulses now in gate.

Run 318

sw 4 + 10mm (319 junk)

Run 320

sw 4 +8mm.

Run 321 junk

Run 322

sw 4 +6mm.

Run 323

sw 4 +4mm.

Run 324

sw 4 +2mm.

Run 326

shift in 1 mm.

sw 4 +3mm.


Run 327

sw4: 0 mm

Run 328

sw4: +1 mm

Run 329

sw4: +2 mm

Run 330

sw4: +3 mm

Run 331

sw4: +4 mm

Run 332

sw4: +10 mm

Run 333

sw4: +30 mm

Run 334

sw4: +50 mm HV: SW: +1500V GW: +750V, FW: -750V

Achtung: Post experiment stuff

Pulse generator problem. What exactly did we trigger on? Was there a shift in the pulse that was sent to us wrt the gun pulse for generating the ADC (integration) gate? We saw a shifting in the gate. We need to systematically study if there is a shift. Note that things went to hell after run 301. We did not change anything except for the width of the gate from 600 ns to 1000 ns. By increasing the width of the gate we increased the integration time and the ADC peak from PLASTIKA went from two peaks (around channel 200) to a nice gaussianlike peak right at channel 500. [Check this]. At run 301 we had the scintillators in the gate, albeit with rather low gain. We then increased the voltages and adjusted thresholds accordingly. Then mysteriously the scintillators fell outside the gate and we had no ADCs from the scintillators. [Were the operators shifting the beam tune to maximize response from the scintillators?]

The peak then magically came back on run 318 and vanished after run 324. In the best case scenario we have 5 good data points: (1.0, 0.8, 0.6, 0.4, and 0.2 mm).

We know the shift was not due to slop in the translation table. The position at the end of the run 334 was +50 mm. We returned to the zero point shifting the 2-axis by 2.0 units in the GUI (2.0 in).

We need belly buttons, lemo cables, connectors: lemo/BNC. Lots and lots of cables.

We need cleaner and smaller scintillators. Nice undergrad project.

Go Back