Proton Calorimetry/Experimental Runs/2013/Dec9-10

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

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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