Offline analysis of data files S505/R5_780 - R5_814 (corresponding to MBS data files 73-74) 

Can find an analysis of alpha background runs at RIBF, RIKEN for comparison at https://elog.ph.ed.ac.uk/AIDA/816

Beam off - background runs without sources

MBS 73 27.6.22 09:33-11:33 CEST https://elog.gsi.de/despec/S505/204

MBS 74 27.6.22 11:34-13:34 CEST https://elog.gsi.de/despec/S505/206

MBS 75 27.6.22 13:35-16:29 CEST https://elog.gsi.de/despec/S505/209

ADC offsets per https://elog.ph.ed.ac.uk/DESPEC/556

FEE64 configuration

FEE64   a b c d
DSSSD#1 3 4 1 2
DSSSD#2 7 8 5 6

p+n junction FE64s odd numbered


Data analysis assumes

- all LEC ADC data channels with valid ADC offset included (474 of 512 channels)
- no clustering
- no p+n junction side - n+n Ohmic side correlation time gates
- valid LEC events
   0 < p+n junction side multiplicity < 8 
   and
   0 < n+n Ohmic side multiplicity < 8 


Attachments 1-2 - per DSSSD p+n versus n+n multiplicity

Attachment 3 - per DSSSD x versus y

Attachments 4-5 - per DSSSD p+n versus n+n energy (20keV/channel nominal)
                  all combinations of per DSSSD p+n junction and n+n Ohmic energies 
                  with projection of data within window onto x and y axes

                  too many events for natural (U decay series) background
                  off leading diagonal correlations anomalous
                  transverse width of leading diagonal correlation wider than expected - ADC offsets OK?
                 

Attachment 6 - per FEE64 WR timestamp (32.768us/channel)
               FEE64 sync test using pulser data - looks OK

Attachments 7-14 - per FEE64 ADC spectra (5.6keV/channel nominal)
                   note common x/y scale - pulser peak height proxy for peak width

per FEE64 1.8.L pulser peak widths (ch FWHM)

1 11.43
2 16.58
3 12.52
4 17.54
5 9.10
6 12.22
7 17.03
8 16.09

3 of 4 p+n junction FEE64 good (<70keV), 1 of 4 n+n Ohmic FEE64 good - all others < 100keV
Pulser peak indicates noise/gain/offset stable throughout background runs


Attachments 15-22 - per FEE64 ADC spectra (5.6kleV/channel nominal)
                    observe broad peak-like structures (c. 2.8MeV) in first channel of most ASICs? 

Attachment 23 per DSSSD p+n versus n+n energy (20keV/channel nominal)
              valid LEC events
              p+n junction side multiplicity = 1 n+n Ohmic side multiplicity = 1

Attachment 24 p+n FEE64 #0 energy versus each of n+n FEE64s (#1, #3, #5 and #7) energies (20keV/channel nominal)
              valid LEC events
              p+n junction side multiplicity = 1 n+n Ohmic side multiplicity = 1

Attachments 23 & 24 do not unambiguously identify which FEE64s are attached to which DSSSD