Proton Calorimetry/Experimental Runs/2013/Dec9-10

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Include all details of experimental runs from Anastasia's PDFs.

PAGE UNDER CONSTRUCTION

Contents


09/12/13

Cables:

  • HV:
    • 1 (RF1) to Main PMT +ve
    • 3 (RN7) to DeltaE PMT -ve
  • Signal
    • LF6 620 - Main PMT
    • LN7 1720 DeltaE PMT / Discriminator

Distance between beam and scintillator face: 30 cm from edge of collimator

Dark Rate: Main PMT

Voltage (V) Threshold (mV) Rate + Additional Information
1200 76
  • Rate: ~100 Hz
1000 76
  • Amplitude: ~200 mV, after some time 300-400 mV
  • Rate: ~25-30 Hz
900 76
  • Amplitude: 500-600 mV
800
  • Amplitude: 300-400 mV

Dark Rate: DeltaE PMT

Voltage (V) Threshold (mV) Rate + Additional Information
-2000
  • Amplitude: ~140-160 mV
  • Discriminator pulse: ~1 V
  • Small petal, number 2
-1800
  • Amplitude: ~380 mV
  • Rate from direct signal: ~2 Hz
  • Rate from discriminator: ~2 Hz
  • 1000 V, 80 mV signal, 20 Hz before beam switches on
  • Beam switch on: Nothing above background rate


Beam on: 14:50, Monday 9th

  • 60 MeV beam, 2 mm collimator, very low dose, 25.8 MHz frequency of cyclotron
  • Rate: 50-300 Hz for 100 events (switches between the two)
  • Amplitude: 1.5 V over 16 pulses
  • Rise time: ~5-6 ns
High Voltage (V) Charge Sensitivity (fC/LSB) + Other Information File
1000 160 selftrigger_1000V_160fc_001
  • Take high voltage down to 800 V:
    • Amplitude: 500 mV over 16 pulses
    • Rate: ~150 Hz for 1000 events (80 mV threshold) at 800 V (after beam off and on)
    • Recorded at selftrigger_800V_160fc_002
High Voltage (V) Charge Sensitivity (fC/LSB) + Other Information File
800 80 selftrigger_800V_80fc_004
800 40 selftrigger_800V_40fc_005
800 20 selftrigger_800V_20fc_006
800 20
  • 83 second run
selftrigger_800V_20fc_83s_007
800 20
  • 100 second run
ST_800V_20fc_008

Peak at ~9240 ADC

High Voltage (V) Rate Collimator File Comments
800 3.2-4.6 seconds for 1000 events 4 mm ST_800V_20fc_013 Rate ~50-60% higher than with 2 mm collimator
800 ~5 kHz 10 mm ST_800V_20fc_014
800 ~1 kHz 7 mm ST_800V_20fc_015 Rate drops down to 300 Hz occasionally
800 6.5-7 seconds for 1000 events 2 mm
  • ST_800V_20fc_016
  • ST_800V_20fc_017
  • ST_800V_20fc_018
  • Increase current on source (previous V = 200 V)
    • Rate: 0.2-1.8 s for 1000 events
    • Open gas slightly (to ~5-6): 1-2 s for 1000 events
      • High gas: HG_019
      • Reduce dose: HD_020

10 mm lower peak:

  • Mean: 11700
  • σ: 434.4

10 mm upper peak:

  • Mean: 21080
  • σ: 1067

10/12/2013

Notes:

  • Cloth off from this point
  • HV: 800 V, -80 mV threshold
  • Dark current with cloth (lights off): ~4 Hz
  • Dark current with no cloth (lights off): ~3.8 Hz

5 minute run:

  • No cloth
  • 2 mm collimator
  • 20 fC/LSB
  • Beam on: 7s for 1000 events
  • ST_800V_20fc_noC_023

Increase intensity (same collimator): 0.2 cc of gas per minute

  • Rate: 2-4 s for 1000 frames
  • ST_800V_20fc_2to4_024
  • 0.4 cc of gas: no change
  • 0.5 cc of gas: rate decreases
  • 0.7 cc of gas: 5 s for 1000 frames
  • 0.7 cc of gas, tweaked arc current: 1 s to 3 s for 1000 frames
  • 0.9 cc of gas, 0 arc current: 2 s to 6 s for 1000 frames
  • 0.9 cc of gas, 1/4 turn of arc current, 142 V: Rate too high
  • 0.9 cc of gas, 25 V: 0.035-1.9 s for 1000 frames
  • 0.9 cc of gas, 13.6 V: 0.04-1.9 s for 1000 frames (0.04 in most cases)
    • ST_800V_20fc_0.9cc_025

Long gate reduced to 100 ns from 200 ns Pre-trigger reduced to 90 ns from 140 ns Gate offset reduced to 20 ns from 40 ns

  • ST_800V_20fc_0.9cc_100nsgate_027

4 mm Collimator

Gas Flow (cc) Voltage (V) Time Elapsed for 1000 Frames (s)
0.9 6 0.02-1.9
0.8 6 0.025
0.8 0 1.5
0.8 3.7-11.7 0.1-1.8
0.8 11.7 0.01
0.6 16-17 0.02
File Electronics Settings
ST_800V_20fc_0.6_100nsgate_028
  • Long gate: 100 ns
  • Pre-trigger: 90 ns
  • Gate offset: 20 ns
ST_800V_20f_0.6cc_200nsgate_029
  • Long gate: 200 ns
  • Pre-trigger: 90 ns
  • Gate offset: 40 ns
ST_800V_20fc_0.6cc_200nsgate_TH1000ns_030
  • As above with trigger hold off: 1000 ns
ST_800V_20fc_0.6cc_100nsgate_TH1000ns_031
  • Long gate: 100 ns
  • Pre-trigger: 90 ns
  • Gate offset: 20 ns
  • Trigger hold off: 1000 ns
  • Beam stop, wd: 4mm_collimator/beam_stop_selftrigger
    • 4 cm of plastic (perspex)

Rate: 1s for 1000 frames, smaller amplitude

Trigger hold off: 0 Gate offset: 20 ns Threshold: 40 ns Long gate: 100 ns File: 800V_20fc_100nsG_5m_034 Description: 5 minute run with beam stop + beam on

Trigger hold off: 0 Gate offset: 20 ns Threshold: 40 ns Long gate: 100 ns File: 800V_20fc_100nsG_5m_beamoff_036 Description: Run with beam stop and beam off, 5 minutes (for natural background)

Trigger hold off: 0 Gate offset: 20 ns Threshold: 40 ns Long gate: 100 ns File: 800V_20fc_100nsG_5m_beamon_046 Description: Beam background data with beam stop, beam on with list mode dumping on Rate: 2.8-2.9 s for 1000 frames

Trigger hold off: 0 Gate offset: 20 ns Threshold: 40 ns Long gate: 100 ns File: 800V_20fc_100nsG_5m_051 Description: Remove beam stop for a 5 minute run Rate: 0.01-0.014 s for 1000 frames

Increase source intensity, change magnets

  • Switching magnet: 11.7, 0.8 cc gas, 0.4 mA, 300 V source (bending the beam less)
  • 0.008s for 1000 frames

Trigger hold off: 0 Gate offset: 20 ns Threshold: 40 ns Long gate: 100 ns File: 800V_20fc_100nsG_2m_005 Description: 2 minute run

Description: Switching magnet position changed by 1 click Rate: 0.25 s for 1000 frames, sometimes switches to 1.75 s File: 800V_20fc_100nsG_056 Note: Narrower peak, more background

Description: Switching magnet bending the beam more on the other side, setting: 14.0 Rate: 0.12-0.13 s for 1000 frames (bad) File: 800_20fc_100nsG_057

Description: Switching magnet setting: 14.2 Rate: 2.9s for 1000 frames (also bad) File: 800_20fc_100nsG_061

Description: Sweep back the other way, switching magnet: 11.3 Rate: 0.6-2.0s for 1000 frames File: 800_20fc_100nsG_063 Note: Better narrow peak

Back to original settings

  • Switch magnet: 12.3 A
  • Source: 0.1 mA, 200 V
  • Gas off, rate too high

Magnet: 12.3 Source: Off Gas: Off Rate: 0.1-1.8 s for 1000 frames File: 800V_20fc_100nsG_067 Note: Energy and time

Source: 0.1 mA, ~200 V Rate: 0.007 s for 1000 frames File: 800V_20fc_100nsG_068 Note: Energy and time

Magnet: 12.3 Gas: Off Source: Off High Voltage: 800 V Rate: 0.5-1.4 s for 1000 frames File: 800V_20fc_100nsG_070

High Voltage: 900 V 800 V Amplitude: 400 mV 900 V Amplitude: 800 mV Rate at 900 V: 1.1 s for 1000 frames File: 900V_20fc_100nsG_071

Settings: All as above DC Offset: -30 File: 900V_20fc_100nsG_DC-30_074 Note: Strange widening of beam during running

Settings: All as above File: 900V_20fc_100nsG_DC-30_077 Note: Normal

Settings: Back to 800 V for PMT DC Offset: -30 File: 800V_20fc_100nsG_DC-30_081

Linearity (different proton energies with perspex thicknesses)

  • wd: 4mm_collimator/lin

Settings:

  • High Voltage: 800 V
  • DC Offset: -30
  • PMMA Position: ~1.80 upstream from module (units?)
PMMA Thickness (mm) Rate (seconds for 1000 frames) File
5.07 0.5-1.5 800V_20fc_100nsG_DC-30_5.07mm_083
9.8 1-2.7 800V_20fc_100nsG_DC-30_9.8mm_084
14.12 2.7, occasionally 1 800V_20fc_100nsG_DC-30_14.12mm_085
17.94 800V_20fc_200nsG_DC-30_17.94mm_086
19.94 800V_20fc_200nsG_DC-30_19.94mm_087
21.71 800V_20fc_200nsG_DC-30_21.71mm_088

DeltaE/External Trigger

  • wd: 3mm_collimator/deltaE

DeltaE PMT running at 1800 V Rate (no beam): 10 events in 6 seconds (~1.5 Hz) Rate (with beam): 0.3-1.7 seconds for 100 events Threshold: 40 Long gate: 100 ns Gate offset: 40 ns DC offset: 0

Intensity Change by Phase

  • wd: 4mm_collimator/phase

Source settings:

  • Gas: Full
  • High voltage: 800 V
  • Arc current: 1 mA
  • Intensity decreased by phasing
Dephase (°) Rate
10 0.3-1.7 seconds for 1000 frames
15 2.5 seconds for 10 frames
12 2 seconds for 10 frames
11 0.1 seconds for 100 frames (~1 kHz)
File 800V_20fc_100nsG_DC-30_11deg_100
Mean ~8069

Settings:

  • DC offset: -30
  • Long gate: 100 ns
  • Gate offset: 20 ns
Dephase (°) Rate Gas (cc) Current (mA) Mean File Notes
9 0.08 seconds for 100 frames 1.5 0.2 mA
0.08 seconds for 100 frames 0.75 0.2
9 0.1 seconds for 100 frames 0.4 0.2 ~7861 800V_20fc_100nsG_DC-30_9deg_103
0 0.001 in 100 frames 0 0 ~9733 800V_20fc_100nsG_DC-30_0deg_105 Dodgy shifts
800V_20fc_100nsG_DC-30_0deg_110 Rate has gone down by a factor of 3, dodgy
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