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