The SY1527 supply was delivered with three modules.

A cable has been made with LEMO00 connectors to connect to the detector adaptor HV inputs.

The SY1527 needed an external VGA display and ps2 keyboard. The software appears to be windows 98 based and won't boot until the bios is told to ignore drive D.

On boot the Drive A must be skipped. I will provide training when others wish to use the system

Channel 0 is being used and has been tested with a voltmeter to provide the correct voltage at the LEMO00 connections. The control seems to be reliable and trips with over current.

200 volts has been applied to the detector with a final current of 3.9uA. The ramp up/down rate is 1V/second.

The acquisition system was run with  pulser OFF and reference setting of 0x30 on the two negative modules nnaida11 and 12.

The rates were 130K/sec + on both the 11 and 12.

Run down the HV and add a 'scope probe ( 10MR and 11pF ) .

Run up and the 'scope shows 20mv pk-pk mushy noise with occasional 200mV+ bursts.

The acquisition performance did not improve.

Changed the reference on 11 and 12 to 0x90 and switch on the pulser then the rate became 20K to 25K. Stat spectra show that ASIC3 and 4 on these boards are still more active than 1 & 2.

Changed the reference on 11 down to 0x40 and Stat spectrum shows ASIC 3 and 4 become more active.

Added an R/C filter at the HV iput to the adaptor board. Removed the 'scope probe. The filter is the same as used with the HV supply in a box block from PorgamRays.

No real improvement.

Changed 11  & 12 reference back to 0x90.

Waveforms in 12 seem normal.

Back to working on the VHDL changes now.

 I'm running nnaida2 with the PB-5 and an old adaptor.(1pF)

I've seen spectra like this before but previously they have shown apparent digital relationship between the troughs. 

So maybe they show 3 peaks ? 

If so I don't quite understand the mechanism......

I just realised that the shaping time is 0.5uS so maybe that is why ??

In no particular order of priority:

1) Vary ASIC V_DD=3.3V within +/-10% operating range

2) Use 'clean' floating high voltage detector bias
    - check polarity
    - is there a difference between detector local
      ground on p+n junction or n+n ohmic sides of DSSSD? 
    - common or isolated detector local ground for multiple DSSSDs?
    - RFQ submitted for 1x CAEN N1419
    - additional filtering for Emco Q05-5?
    - other?

3) Backtrack changes to date
     - Kapton PCB mods
     - PSU set points
     - Standard FEE64 PSUs -> linearly regulated PSUs

4) Evaluate effect of ASIC parameters 'Ibias preamp SF' and 'Ibias preamp' on noise

5) Evaluate effect of ASIC parameter 'preAmp reference' on stability of positive and 
   negative input configurations

Comments and corrections welcome!

Changes from configuration described by Elog entry https://elog.ph.ed.ac.uk/AIDA/3
are as follows:


HV

Emco Q05-5 ISOLATED, PROPORTIONAL DC TO HV DC CONVERTER

Input TTi QL355T set +1.5V, Emco Q05-5 output +194.6V

Output RC filter 1uF x 1MOhm

i.e. a filtered, floating high voltage detector bias supply
cf. NIM-bin grounded Silena 7710 Quad Bias used previously


ASIC Adaptor PCB

nnaida11 & nnaida12 LK 3 & 7
nnaida13 & nnaida13 LK 1, 3, 5, & 7

HV + -> nnaida11 & nnaida12
HV - -> nnaida13 & nnaida14 
DSSSD grounded locally at nnaida12 & nnaida13 adaptor PCBs
by ground links LK 1 & 5 (cf. Silena 7710 Quad Bias Supply
used previously).


ASIC settings

Default ASIC settings (see attachments 1-4)


Observe stable operation of both positive and negative polarity
FEE64s using default ASIC parameters and a floating HV detector
bias supply


Attachments
1-4 nnaida11, 12, 13, & 14 ASIC settings
5-8 nnaida11, 12, 13, & 14 hit/rate patterns
9-12 nnaida11, 12, 13, & 14 ASIC # 4 ADC spectra
13 nnaida12 ASIC # 1 waveforms
14 nnaida14 ASIC # 1 waveforms
15 Emco Q-series catalogue

MSL type BB18-1000 2998-22 bias +200V I_L +3.27uA

BNC PB-5

amp 2.0V
atten x1
tau_d 1ms
freq 200Hz
pol - (output split via EG&G Ortec 433A to generate + polarity too)

PSU

TTi QL355TP  "-6V & +7V" output set @ -7V & +8V, @ FEE64 -6.7V & +7.3V 
TTi QPX1200S "5V" output set @ +6.2V, @ FEE64 +5.3V
 'linearly regulated output' PSUs  connected via standard FEE64 PSU chassis

Adaptor

nnaida11 & nnaida12 - polarity input (n+n ohmic strips)
  MSL type BB18 adaptor PCB rev 180713 LK 3 & 7
nnaida13 & nnaida14 + polarity input (p+n junction strips)
  MSL type BB18 adaptor PCB rev 180713 LK 1, 3, 5 & 7

FEE64

Note nnaida11 has been modified to remove the 470 Ohm resistors
linking the buffered preamp outputs from the ASICs to the buffer
amplifiers at the sampling ADC inputs. This effectively reduces
to zero the switching current load on the buffered preamp outputs. 

ASIC parameters

  standard *except* nnaida11 & nnaida12 preAmp reference 0x20 -> 0x90
  which will reduce linear output range by c. x2 but significantly stabilises
  negative polarity input ASICs

  varying nnaida11 & nnaida12 'Ibias Preamp SF' and 'Ibias Preamp' from 0x8 -> 0x0
  had marginal effect on stability and degraded ADC spectra

Typical pulser peak widths for nnaida11, 12 (ASICs #1-3) and nnaida13, 14 (ASICs #1-4)
c. 130-150ch FWHM.

Attachments

1-4 nnaida11, 12, 13, & 14 ASIC parameters
5-8 nnaida11, 12, 13, & 14 hit/rate patterns
9-12 nnaida11 ASICs # 1-4
13-16 nnaida12 ASICs # 1-4
17 nnaida13 ASIC # 4
18 nnaida14 ASIC # 4
19 nnaida11, 12, 13 & 14 'good events' statistics

 This is very interesting. Look forward to many happy interactions.

The AIDA Elog is now operational and can be found at

https://elog.ph.ed.ac.uk/AIDA/