STAR BARREL PRESHOWER:
a collection of stuff relevant to electronics hookup and mapping issues
(or things I think I know and many I don't -> so far 4/1/06 -- wwj)
BEMC master hookup spreadsheet -> PreShower
- The master BEMC hookup spreadsheet as updated by
Oleksandr Grebenyuk is available
here as .ppt or
here as .pdf,
and the schematic pictorial layout on STAR is
- As indicated there are 4 PRS readout crates, 2 on the west and 2 on the east.
Each crate has 15 "slots" of readout (simialar to the SMD) for a total of 60
slots (e.g., the number of PMT boxes for the full Barrel and hence the mapping
of PMT boxes to crate readout slots).
- The Preshower signals from a
PMT box are carried to a slot on a crate by a single cable (contains
both "A2" and "A1" portions, see more on this later). The association of RDO's,
crate slots and PMT boxes for 2006 (run_6) hookup is given in table
BPRS scheme of connections
This hookup order is as received from Oleg Tsai 2/1/06 and written in to
StEmcDecoder by Alex Suaide. That code is located
- Combining the tower information of 1.1 spreadsheet with the card/slot
readout association of 1.3, I generated a
.xls spreadsheet or
here in .pdf
gives the nominal tower ID ranges for the 80 towers mapped from each
PM box to the RDO crate card/slots. If the cables from from the PMB to
crates are hooked up correctly, we then know what readout electronics
the signals from each PMB. Further division and distribtution of these channels
is discussed below.
- Crate electronics scheme: PRS vs. SMD
Here are some documents (this and next items) from Phil Kuczewski
relating to the PreShower electronics
(so far they are just scanned in hard copies but hope to get original
- The crate "slot" to SMD equivalent wire and AMB board mapping
is given here. The preshower uses
just the first two "connectors" (A1 and A2) of each slot, and correspondingly
the first two inputs to each of the 5 AMB boards of the crate. The SMD wire
correspondence is not exactly right ... it is actually offset by one for
each SCA channel (see next), but general mapping is correct.
- The association of channel number vs. SCA input and channel amp
is given here for the A1 and A2 connectors used
for the preshower. Note: the SMD only uses 15 out of the 16 SCA inputs
(e.g., omitting the first channle in each case) so that the association with
SMD wire number is incorrect in the table (well, I have corrected by hand)
... really, for SCA 1, wire 300 <-> SCA input 2;
for SCA 2, wire 270 <-> SCA input 2; for SCA 3, wire 240 <-> SCA input 2.
Anyway, one sees that the preshower uses only 1/2 of the readout associated
with the first two connectors (2 and 1/2 SCA's each).
- This block drawing shows the J1 -> J5
connections (whose preshower channels are indicated in table linked just
above) to the channel amps. The channel amps are grouped in
bunches of 8 and one assembly of 5 clamps is 40 channels of preshower
(corresponding to either a complete A1 or A2 connector). So, two clamp
assemblies readout a PMT box (or crate slot).
In the following, the SMD documentation (also from Phil) is
linked. Remember that
the preshower electronics uses essentially the same readout scheme. Here
the correspondence with SMD wire number and other electronics features
become more apparent in the following.
- The SMD crate slot mapping is given here.
- SMD FEE assembly input mapping is here.
- Crate cable map for SMD is here.
- SMD FEE board layout is here (not so relevant
for the preshower I think but interesting for SMD)
- Other Mapping Information
- From Marcia, a collection of PMT box hookup docs and final tower to
crate associations is given at
this link .
- More info coming from old Wayne State/Riso docs ....
- Preshower ADC Spectra
Listed in the following are spectra obtained so far that I could get my
hands on ..
- With the initial install of 2 preshower crates on the west, Martijn
analysed some runs and presented spectra vs. ID with current unpacking
software. The spectra (annotated with respect to PMT box and crate slot#)
here (note: open as .ppt to see whole spectrum which
is slightly oversize).
Some overall observations are:
- See only "peds" for PMB's # 30, 1, 8 and 9. Originally thought this might
mean no HV to these tubes? but later spectra (see below) seems to give
reasonable ADC values.
- For Crate 0xMMMM, the channels corresponding to the A2 connector
(lowerst channel ID numbers from a box appeat to be oscillating for
ever third slot. This corresponds to the last inputs on each of the
5 "AMB" boards for the crate.
- There are many "corrupt" looking segments of the spectra, with sequences
of 4, 8, 12 contiguous channels in different patterns. Not all of these
persist in subsequent spectra, although in principle they can give insight
into the mapping scheme via known possible hardware failure modes vs.
observed ID (unpacked) spectra.
- The "multi-peaked" nature of the ped spectrum is likely due to
significantly different contributions from the last 2 capacitors of the
SCA readout (e.g., similar to that observed with the SMD, for which those
capapcitors are discarded). BTW, proper treatment would involve storing
a ped for each capacitor.
- A more recent spectra (from Martijn et al.) taken after install of the
east side lower crate (total of 3 out of the four crates), is given