preamp B detector (DSSSD 2) on 100 V, DSSSD 1 still on 70

Here is a brief status update on the chamber setup.

At the moment, we have all the main components required for the experiment related to the chamber:

• Vacuum chamber

• 2 × MSL type W DSSSDs

• 2 × MSL type W1 preamplifier units

• Sample support, feedthrough, and short cables

• 4 fans for the preamplifiers

• 2 cases for the preamplifiers

• Samples: 2 NaCl, 1 Boron, 1 Lithium, 1 dummy, and 1 empty

• Bias voltage cables for the preamplifiers

Please find attached some photos showing the current setup.

The only remaining item to be installed is the fans, which will be connected on Monday, February 2nd. We may also try installing the detectors soon; we have already tested the fit with a spare detector, and it fits well.

Additionally, the distance from the center still needs to be measured so that we can precisely determine the sample position from outside the chamber. We will need to add a reference mark for this.

Finally, if we decide to position the detectors further away from the beam, we will require longer bias voltage cables for the preamplifiers.

Please let me know if you need any further information.

After the first weekend, we change the setup configuration. We removed the shadow cone, and we placed the chamber closer to the LiF target.

The voltage was increased upto 100V for both detectors, but there was a problem in DSSSD1. Therefore, The voltage was setup at 70V for DSSSD #1 and 100V for DSSSD #2.

The chamber was placed at 6.5 cm form the LiF target. That's mean that the sample is placed at 14.1 cm from the LiF target.

IMPORTANT!!!

The sample is toward detector DSSSD #2. So, the sample is placed at 2.5 cm from DSSSD #2 and 2.7 cm from DSSSD #1.

DSSSD #2 is the upstream detector and DSSSD #1 is the downstream detector.

Gold + Mylar sample in beam

Starting time: 15:32:00

Stop time : 08:13:55

Blocks : 123407

Flux monitor

Starting time : 16:27:58

Duration: 60118

IMPORTANT!!!

The clocks are not sincronize

Am-241 calibration source. Towards DSSSD #2 (PreAmp B) upstream detector

Starting time: 08:41:21

Stop time :

Blocks :

The activity of th source is 0.1 uCi

LiF #7 sample in beam

Starting time: 15:11:10

Stop time : 08:14:22

Blocks : 138311

Flux monitor

Starting time : 16:07:05

Duration: 613911

IMPORTANT!!!

The clocks are not sincronize

LiF #8 sample in beam

Starting time: 08:34:15

Stop time : 14:53:02

Blocks : 55124

Flux monitor

Starting time : 09:30:14

Duration: 22727

IMPORTANT!!!

The clocks are not sincronize

Boron-10 #3 sample in beam

Starting time: 08:49:16

Stop time : 15:07:34

Blocks : 44619

Flux monitor

Starting time : 09:45:09

Duration: 22696

IMPORTANT!!!

The clocks are not sincronize

NaCl #5 sample in beam

Starting time: 15:29:51

Stop time : 08:19:57

Blocks : 99805

Flux monitor

Starting time : 16:25:55

Duration: 60601

IMPORTANT!!!

The clocks are not sincronize

Before this run, we change the target for the neutron source. We are using a Triton target of ~200 ug/cm².

Starting time: 11:14:32

Stop: 15:03:16.

Flux monitor

Starting time: 12:10:44

Duration: 13723

start: 08:24:49, 3.3.2026
stop: 10:13:25
blocks: 3062

Flux monitor

Start: 09:20:43

Duration: 6531

LiF no. 7 in beam

Start: 15:45:30, 2.3. 2026

Stop: 07:57:05 3.3. 2026

Blocks: 25524

Flux monitor

Start: 16:41:41 of 2nd March

Duration: 58288

NaCl Target 5

start: 13:28:38, 2.3.2026
stop:  15:05:22, 2.3.2026
blocks:   2206

LiF no. 7 in beam

start: 10:14:0531 2.3.26
stop: 12:57:08 2.3.26
blocks: 3855

NaCl No. 4

start: 09:36:05 2.3.26
stop: 09:43:49 2.3.26
blocks: 14

Cu rod taken out, run in neutron beam with NaCl target. Distance chamber to target is 6.5 cm. Run stopped due to high trigger rate in channels 138,144. 

start: 16:14:44 27.2.26
stop: 08:38:26 2.3.26
blocks: 48895

no change from R52

Start: 15:06:06 GMT
Stop: 16:13:45
Blocks: 875

Sample: NaCl + Au Frame #4
Beam on target, 2.25 MeV neutron energy, 10 uA protons on LiF 410 ug/cm2 target
Shadow cone, copper rod, 30 cm
Pulser: frequency 20 Hz, amplitude 5 V, other settings per R51
Upstream detector, preamp A, S9418#1
Downstream detector, preamp B, S9418#2

All RAL109 LLD 20mV

DAQ triggers c. 44Hz, accepted c. 40Hz

15.57.21 CET Stopped moderated BF3 monitor ABCD acquisition
Digitizer reconfiguration
15.57.31 Started moderated BF3 monitor ABCD acquisition

15.57.52 Stopped moderated BF3 monitor ABCD acquisition
Digitizer reconfiguration
15.57.56 Started moderated BF3 monitor ABCD acquisition

R52 stopped to permit change to BF3 counter DAQ configuration

start: 14:31:03 (w23 is set to GMT)
stop: 14:38:09
blocks: 98

Pulser walkthrough - amplitudes 5.0-1.0 @ 1.0 step

Attachment 1 - screenshot of all 64x ADC spectra with common x/y-scales
               n+n Ohmic strips lower resolution cf. most p+n junction strips - increase DSSSD bias?

Offline data analysis of data file R52 
c. 1h 2.25MeV neutrons from 10uA p+ + 410ug/cm2 LiF -> copper block -> sample #4 Mylar+NaCl+197Au 

ADC data are offset corrected but not gain matched.

Attachments 1-2 - DSSSD#1 and DSSSD#2 ADC spectra (10keV/channel nominal)

Attachment 3 - ADC hit pattern (DSSSD#1 0-15 p+n/16-31 n+n, DSSSD#2 32-47 p+n/48-63 n+n)

Attachment 4 - energy (10keV/channel nominal) versus channel (DSSSD#1 0-15 p+n/16-31 n+n, DSSSD#2 32-47 p+n/48-63 n+n)

Attachment 5 - per DSSSD p+n junction energy - n+n Ohmic energy + 2048 (10keV/channel nominal) - with/without energy difference gates currently set to 1948-2148 (i.e. 
non-
selective) 

Attachment 6 - per DSSSD p+n junction energy versus n+n Ohmic energy (20keV/channel nominal) - with/without energy difference gates currently set to 1948-2148 (i.e. 
non-selective) 

Attachment 7 - scaler spectra (1000x rate updated every 60s)

Attachment 8 - sort program variables

Issues

From pulser tests and pulser walkthrough (R51) all channels are OK *except* channels 14, 40, 41 with no data

From data with beam (R52)

Channels 24-31 - little data - check RAL109 LLD? 

Channel 23 - no ADC data => issue between preamp and Si wafer or RAL109 discriminator

Channel 36 - low amplitude ADC data => issue between preamp and Si wafer

Channel 58 - no ADC data => issue between preamp and Si wafer or RAL109 discriminator

MIDAS DAQ configuration files

/MIDAS/experiments/daq/VMEDataSources - attachment 1
/MIDAS/experiments/daq/MidasOptions - attachment 2
/MIDAS/experiments/daq/VMEConfigs/latest - attachment 3
/MIDAS/experiments/daq/VMESetups/latest - attachment 4

MIDAS Tape Server console ( /MIDAS/TapeServer/SunOS/master ) and MIDAS log (e.g. tail -f /MIDAS/log/27Feb26 ) - attachment 5

MIDAS DAQ configuration, Silena 9418/6V controls and CAEN V560 scaler - attachments 6-8 

BNC PB-5 settings
Amplitude 5.0V
Attenuator x10
Decay time 1ms
Polarity +
Frequency 20Hz
Delay MIN (250ns)


Silena 7710 Quad Bias
Channel 1 connected to preamp A, channel 2 to preamp B
DSSSD#1 (preamp A) bias -70V I_L -0.11uA
DSSSD#2 (preamp B) bias -70V I_L -0.10uA


CAEN V560 Scaler
Channel
0  Triggers
1  Triggers accepted (STFC DL SAC Mon 2 output )
2  Clock (1kHz) 
3  Pulser (positive NIM logic output -> negative NIM output via Phillips 794)
4
 :
 :
9  OR DSSSD#1 p+n strips 0-15
10 OR DSSSD#1 n+n strips 0-15
11 OR DSSSD#2 p+n strips 0-15
12 OR DSSSD#2 n+n strips 0-15


CAEN V560 scaler channels 0-4 read per event

DAQ Trigger
DSSSD#1 n+n strips OR DSSSD#2 p+n strips OR DSSSD#2 n+n strips (LeCroy 429A)
DAQ trigger re-shaped from c. 100ns to c. 1us by Phillips 794

Logic cable #4 appears to kill 48-way OR logic module - workaround - cable 4 disconnected - scaler #9 no reading 


Silena 9418/6V ADC settings
RTP 0 (2us)
LLD 6 (48 channels)


No ADC data from 3 channels
S9418#1.adc14
S9418#2.adc8
S9418#2.adc9

All other channels appear to be OK
Pulser peak width c. 7 ch FWHM p+n strips, c. 8 ch FWHM n+n strips
See attachments 8-11

RAl109 amplifier output DSSSD#1 p+n strip 0 - attachments 1, 2 and 4 - beam OFF, no significant extrinsic noise


Photograph of experiment electronics and sample chamber - attachments 3, 5-7

Analysis of how the current changes with increasing voltage for both detectors.

Detector 100 um.

Detector 150 um.

Attached is the plot showing the comparison between voltage and current.

The first sample on beam is the NaCl target #4. The shado cone was placed between the LiF target and the chamber.

The shadow cone was a cupper cilinder of 4cm diameter and 30 cm lenght, placed at 0.8 cm from the LiF target and 2.8 cm from the chamber. See first figure 1.

Therefore, the diameter of the chamber is 15cm. The sample (considering the center of the chamber as 0) it's place 1 mm misalignt farther from the beam. So, the distance between the LiF target and the sample is 41.2cm.

On the other hand, the distance between detectors is 5.2cm, and the sample is closer to the upstream detector. So, the sample is at 2.5cm from DSSSD #2 (Preamp B) and at 2.5cm from DSSSD #1 (Preamp A). See Figure 2.

DSSSD 2 goes to ADC9419 1; DSSSD 1 goes to ADC9418 2;

Au layer faces DSSSD 1. NaCl target 4. 

Both detectors were setup at 70V on Friday 27th of February.

Concerning the electronic stuff. We will need:

• 1x NIM bin.
  • Pulser (Model PB-5)
  • Sum&Invert (Model 433A)
  • Bias supply (Mod. 7710)
• 2x MSL type W1 preamplifier units.
• 4x flat cables.
• Jonction Box.
• 1x 9U KM-6 sub-rack (10x RAL109 amplifier modules)
• 8x flat cables & 16x output in one side.
• 1x CAMAC crate (2x 48-input OR)
• x lemo cables
• 1x VME V430 crate.
  • cpu.
  • scaler.
  • sac.
  • 3x Silena ADCs.
• 1x Sun Ultra 45 workstation (flat panel, keyboard, mouse).

Count rate estimate for all reaction measurements planned. 

Assumptions:

• Neutron source 7Li(p,n); default setttings. 
• Distance of sample to target: 30 cm
• solid angle coverage: 0.4
• areal density of samples very roughly estimated from alpha energy loss measurement from  Daresbury
• includes calculation of expected particle energies at 0 and 180 degrees emission. 

Conclusions

• All particles at all neutron energies should be stopped in 150 um detector. If one of them breaks, the 100 um detector should be installed at backward angles.
• sufficient counting statistics for few hours running per target.

BOX A

1) VME V340 crate, fan tray. Serial number 3797053, type UEL 6020.

2) VME V340 crate. Serial number 1996008, type UEV 6021.

3) VME power supply. Serial number 1896026, type UEP6021.

4) 1x CPU, MVME 2431. No serial number.

5) 1x Scaler, module V560M, serial number 310.

6) 1x ACQ control, for trigger, S1418. No serial number.

7) 3x Silena. 1) mod. 8418/6V. Serial number 108.

8) 2) Serial number 195.

9) 3) Serial number 192.

10) Flat cable to couple the threee SILENA modules with the cpu.

11) 3x Ethernet cable.

12) Power cable for VME.

13) Power cable for the VME.

BOX D

1) 10x RAL camplifier modules.

2) Standar fan tray, RS company. Serial number 46377.

3) 1x 9U KM-6 sub-rack (10x RAL109 amplifier modules). No serial number.

4) Junction box.

5) Power cable for the crate and for the fan tray.

BOX C

1) 1x CAMAC crate (2x 48-input OR), Le Croy, model 1434A. Serial number A38496.

2) 1x CAMAC crate power supply. Serial number A49732.

3) 2x 48-input OR. No serial number.

4) Power cable for the CAMAC crate.

5) Bipolar power supply +/- 15 V. No serial number.

6) Power cable for the Bipolar power supply.

7) Quad bias supply mod-7710 mat. 045 .

8) Pulser (Model PB-5). Serial number 33802.

9) Sum&Invert (Model 433A). model 433A ORTEC. Serial number 142.

BOX B

1) 1x Sun Ultra 45 workstation. Serial number 0743TFC0DF.

2) Mouse. Serial number 0581MCN-0714NC0175.

3) Keyboard. Serial number 0581MCN-0642NY5023.

4) Screen monitor.

5) 8x flat cables. From 9U KM-6 sub-rack to CAMAC crate and SILENA.

6) Ethernet switch. Serial number A03276G083700812 A.

7) 3x Power cable.

8) Logic Fan-in/Fan-out, Le Croy, model 429A, Serial Number B59330.

9) Extra A box.

10) New Jonction box.

Extra A

1) Connector for +- 15V & +- test.

2) 7x lemo cables.

3) 4x voltage cables.

4) Power cable for the fan of the preamp.

5) Extra cables for checking signals.

6) Flat cable with 8 channels.

7) Flat cable for voltage of the preamp.

8) Spare connection from preamp to feedthrough or detectors.

BOX E

1) Chamber and the sample/detector support.

2) 2x MSL type W1 preamplifier units. No Serial number.

3) Plate for the chamber.

4) Tripod for the chamber.

5) Manomiter for pressure reader.

6) Valves for vacuum.

7) Screws and cable connection from preamp to feedthroug and detectors.

8) Screws for detector and sample holder.

BOX F

1) 2x 150 um DSSSD detectors.

2) 1x 100 um DSSSD detector.

EXTRA BOX

1) Cable Extender.

T=0: Edinburgh Time 9:39:00

T=1:40: Geel Time 10:37:00

--> T_diff Geel - Edinburgh = 10:35:20 - 9:39:00 = 56:20 

The cables are plug in this way.

Cable 0 connected to Preamp A, Positive output. (n+n side, toward the sample)

Cable 1 connected to Preamp A, Negative output. (p+n side, backward the sample)

Cable 2 connected to Preamp B, Positive output. (n+n side, toward the sample)

Cable 3 connected to Preamp B, Negative output. (p+n side, backward the sample)

Then, each cable goes to the jonction box:

Cable 0 goes to label unused. This goes to cable 5 and 6. The output from the RAL amplifier is cable 15 A/B

Cable 1 goes to label 6. This goes to cable 9 and 10. The output from the RAL amplifier is cable 14 A/B

Cable 2 goes to label 5. This goes to cable 4 and 8. The output from the RAL amplifier is cable 13 A/B

Cable 3 goes to label 4. This goes to cable 1 and 3. The output from the RAL amplifier is cable 12 A/B

From the RAL amplifier.

Cable 12 goes to Silena 9418 #1 0-15 channels.

Cable 13 goes to Silena 9418 #1 16-31 channels.

Cable 14 goes to Silena 9418 #2 0-15 channels.

Cable 15 goes to Silena 9418 #2 16-31 channels.

Therefore,

the Preamp B is plotted in Silena 9418 #1, n+n side channels 16-31 and p+n side channels 0-15.

the Preamp A is plotted in Silena 9418 #2, n+n side channels 16-31 and p+n side channels 0-15.

Plot from Fran showing peak around expected proton energy in both detectors. Top half are strips of detector placed at 180degrees wrt neutron beam, bottom half 0 degrees. Hence, proton peak from bottom half should be at slightly higher energy.