Welcome to the FTPC Homepage
First FTPC Event
The FTPC data aquisition system is tied in with the main STAR DAQ. From the receivers onward, all hardware components are identical. The software for the electronics channel mapping is committed to the STAR cvs repository $CVSROOT/online/ftpc/MapFtpcElectronicsToDaq
The signals from the FTPC electronics are sent to DAQ where each
readout board,mezzanine card,asic is mapped to an FTPC sector,daqrow,daqpad.
HARDWARE:
2 identical FTPCs - Ftpc West = 1, Ftpc East = 2
5 rings/FTPC
2 padrows/ring
10 padrows/FTPC
6 sectors/padrow
6 sectors/padrow x 10 padrows/FTPC = 60 hardware sectors/FTPC
160 pads/sector
9600 pads/padrow
= 19200 electronics channels for both FTPCs
ELECTRONICS:
20 readout boards (RDOs)
10 RDOs/FTPC
3 mezzanine cards/RDO
= 3 mezzaanine cards/RDO x 10 RDOs/FTPC = 30 electronic sectors/FTPC
DAQ:
The signals from the FTPC electronics are mapped to the hardware with the FTPC_PADKEY.h file.
DAQ notation:
30 daqsectors/FTPC (Ftpc West 1-30, FtpcEast 31-60)
2 daqrows/daqsector
320 daqpads/daqsector = 2 x 160 daqpads/daqrow
Ftpc Ring Padrow Sector daqrow daqpads
1 1 1,2 1,7 1,2 1-160
2,8 1,2 161-320
3,9 1,2 321-480
4,10 1,2 481-640
5,11 1,2 641-800
6,12 1,2 801-960
2 3,4 13,19 1,2 1-160
14,20 1,2 161-320
15,21 1,2 321-480
16,22 1,2 481-640
17,23 1,2 641-800
18,24 1,2 801-960
3 5,6 25,31 1,2 1-160
26,32 1,2 161-320
27,33 1,2 321-480
28,34 1,2 481-640
29,35 1,2 641-800
30,36 1,2 801-960
4 7,8 37,43 1,2 1-160
38,44 1,2 161-320
39,45 1,2 321-480
40,46 1,2 481-640
41,47 1,2 641-800
42,48 1,2 801-960
5 9,10 49,55 1,2 1-160
50,56 1,2 161-320
51,57 1,2 321-480
52,58 1,2 481-640
53,59 1,2 641-800
54,60 1,2 801-960
2 1 1,2 6,12 1,2 1-160
5,11 1,2 161-320
4,10 1,2 321-480
3,9 1,2 481-640
2,8 1,2 641-800
1,7 1,2 801-960
2 3,4 18,24 1,2 1-160
17,23 1,2 161-320
16,22 1,2 321-480
15,21 1,2 481-640
14,20 1,2 641-800
13,19 1,2 801-960
3 5,6 30,36 1,2 1-160
29,35 1,2 161-320
28,34 1,2 321-480
27,33 1,2 481-640
26,32 1,2 641-800
35,31 1,2 801-960
4 7,8 42,48 1,2 1-160
41,47 1,2 161-320
40,46 1,2 321-480
39,45 1,2 481-640
38,44 1,2 641-800
37,43 1,2 801-960
5 9,10 54,60 1,2 1-160
53,59 1,2 161-320
52,58 1,2 321-480
51,57 1,2 481-640
50,56 1,2 641-800
49,55 1,2 801-960
FTPC expert(s) currently on call:
Alexei Lebedev alebedev@bnl.gov Phone: 3101 Cell phone: 631 255 4977
TO ALL DETECTOR OPERATORS:
Voltage Settings | |
Cathode voltage (2 channels) | -10kV±5V |
Anode voltage (2x6 channels), Physics | +1800V ±2V West, +1800V ±2V East |
Anode voltage (2x6 channels), laser | +1200V±2V West, +1200V±2V East |
Anode voltage (2x6 channels), pedestals | +1000V±2V West, +1000V±2V East |
Anode voltage (2x6 channels), stand by | 0V West/East, (+~15V are displayed) |
Gating grid (2x4 channels) | -76V±2V open, -76V±115V closed |
Y2007/2008 Standard Values | |
Water pressure in (West/East) | -400mbar -> -100mbar |
Water temperature (West/East) | <31 C |
O2(ppm) (West/East) | <10ppm |
H2O (dp C) Westt/East) | <-50 C dp |
Ar flow = CO2 flow (West/East) | 72l/h->78l/h; West=East |
Cathode current | 0.14mA |
Anode current | -15nA < I < 15nA |
For more information, please consult:
The pad monitor we use was developed by Andreas Schuettauf. It is referred to as the Munich Pad Monitor. (The FTPC pad monitor development was started by Jennifer Klay in Davis. Her documentation contains alot of useful information. Unfortunately, Jennifer left STAR before she finished the pad monitor.)
Welcome! You have found the webpage dedicated to providing information and documentation on the FTPC PadMonitor. The FTPCs (Forward Time Projection Chamber) are a key sub-system of the STAR Experiment at RHIC. The PadMonitor is a software program designed to allow for monitoring of FTPC performance. The program can be separated into two basic parts: the GUI (Graphical User Interface) and the data I/O interface. The GUI has been designed using Java with the data I/O interface provided by the Java Native Interface to C and C++ code. This choice of languages reflects the desire to marry cross-platform transportability with legacy code already written for STAR DAQ data. In addition, we hope to be able to run the PadMonitor as a Servlet or Javascript from the Web, allowing collaborators access to view detector performance or issue trigger commands from a distance.
STAR DAQ Home Page This is the local working home page for the DAQ Group. Specific links of interest on this site include:
Main TPC
24 Sectors-each one handled by a single VME crate
Each VME crate contains 6 receiver boards and one "Sector Broker" (to handle global sector characteristics and communication)
Each receiver board contains 3 mezzanine boards which buffer the data and host the STAR Cluster Finding ASICs (pedestal subtraction,gain correction, 10bit->8bit data conversion, 2D cluster finding)
To reconstruct a single sector's data, one must gather:
From each of six receiver boards, the contributions from all three mezzanine boards
384 pads per sector
45 padrows per sector
Number of pads per padrow variable (due to wedge-shape of sectors)
512 timebins per pad
Forward TPCs
2 Chambers-each one handled by a single VME Crate
Each crate contains 10 receiver boards and one "Chamber Broker" (performs the same functions as the Sector Broker but for a single FTPC Chamber)
Each receiver board handles three FTPC Sectors (30 sectors per chamber)
Each receiver board has 3 mezzanine boards. The simplest sector->mezzanine mapping is 1:1, but may not necessarily be so. In order to be general, the pointer structure is set up such that from the receiver board, one points to a sector and from the sector one points to the mezzanine board.
To reconstruct a single sector's data, one must gather:
From one receiver board, the sector via contribution from one mezzanine board
30 sectors per chamber
320 pads per sector
2 padrows per sector
160 pads per padrow
512 timebins per pad
Ideally, one would like to hide this heirarchy behind a simpler user interface. This has been done by making the FTPC Format Reader very similar to the main TPC. Users request data from a specific sector, numbered 1 to 60 (1-30 for West FTPC, 31-60 for East FTPC). The user numbering scheme follows the FTPC Cabling design drawings. The mapping to correct receiver board and mezzanine contributions for a given sector is provided by a header file included with the Format Reader.
FTPC Raw Data Format Document (postscript)
View some schematic pictures of the DAQ design and the current Raw Data Format:
The following is a diagramatical sketch of the information path explained in the DAQ Raw Data Format Document.
Group |
Task Description/Problems |
Location of Source Code |
Contact |
DAQ |
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Map FTPC electonics to DAQ |
$CVSROOT/online/ftpc/MapFtpcElectronicsToDaq |
Janet |
|
FTPC "gain table" for DAQ |
|
Frank |
Online |
|
|
|
|
FTPC Detector Control |
/afs/rhic.bnl.gov/star/doc_public/www/ftpc/Operations |
Terry |
|
Slow Control |
|
Terry |
|
FTPC Slow Control Monitoring Facility |
|
Terry |
|
Pad Monitor |
$CVSROOT/online/ftpc/FtpcPadMonitor |
Janet |
|
Online Tools: |
|
Terry Janet |
|
Online histograms ("Panitkin plots") |
|
Janet |
Drift Velocity Monitor |
OBSOLETE |
|
|
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LabView program running on bond.starp |
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bond.starp -> virgo.starp samba connection |
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virgo.starp cron job - copies files from /DV2/Today to /DV2/Store |
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Conversion of DVM data files to root format |
|
|
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StFtpcDVMMaker - DVM data analysis programs |
$CVSROOT/offline/StFtpcDVMMaker |
|
Calibration |
|
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|
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Noise Finder: |
|
Terry |
|
Drift Maps:
Magboltz2 |
$CVSROOT/StRoot/StFtpcDriftMapMaker $CVSROOT/online/ftpc/Magboltz2 |
Janet |
|
Laser Analysis: |
|
Terry |
Databases |
|
|
|
|
Slow Control -> Online database -> Offline database |
|
Terry |
|
Offline database: |
|
Terry |
|
StDb/idl - idl definition files for FTPC database tables |
$CVSROOT/StDb/idl |
Janet |
Simulation/ Reconstruction |
|
|
|
|
StFtpcSlowSimMaker |
$CVSROOT/StRoot/StFtpcSlowSimMaker |
Frank |
|
StFtpcClusterMaker |
$CVSROOT/StRoot/StFtpcClusterMaker |
Joern |
|
StFtpcTrackMaker |
$CVSROOT/StRoot/StFtpcTrackMaker |
Markus |
|
pams/ftpc/idl |
$CVSROOT/pams/ftpc/idl |
Janet |
QA |
|
|
|
|
St_QA_Maker |
$CVSROOT/StRoot/St_QA_Maker |
Gene Janet |
Embedding |
|
|
|
|
StFtpcMixerMaker |
$CVSROOT/StRoot/StFtpcMixerMaker |
Frank |
Analysis |
|
|
|
|
StFtpcMcAnalysisMaker |
|
Frank |
ITTF |
|
|
|
|
StiFtpc |
$CVSROOT/StRoot/StiFtpc |
Maria Mora-Corall |
Documentation |
|
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|
|
Web pages |
/afs/rhic.bnl.gov/star/doc_public/www/ftpc /afs/rhic.bnl.gov/star/doc_private/www/ftpc |
Janet |
This page was written by Janet Seyboth on Febuary 10, 2004
This page was created by Janet Seyboth on March 7, 2006
StFtpcClusterMaker Documentation
If raw data already exists, either produced by the FTPC slow simulator (StFtpcSlowSimMaker) or from a daq data import, StFtpcClusterMaker will immediately invoke the cluster finder StFtpcClusterFinder . Otherwise, the FTPC fast simulator StFtpcFastSimu will be invoked to generate hits from geant data.
The StFtpcTrackMaker replaces St_fpt_Maker in the FTPC reconstruction chain.
StFtpcTrackMaker uses the clusters from StFtpcClusterMaker to reconstruct the tracks in the FTPC using conformal mapping. A list of all the "found" hits along with the number actually found and the maximum number of hits possible are saved for each track.
Then these "found" hits are fit using a 2x2-D track fitter. The impact parameter at the pre-vertex is calculated. All tracks with an impact parameter less than max_Dca are flagged as primary track candidates whose vertex is the pre-vertex. The momentum fit results for the unconstrained fit are saved in the track table.
14553 Geant hits (about 1000 tracks per Ftpc) after being tracked with the new Conformal Mapping Algorithm.
Last modified: Apr 20 2005
This page shows results of some tests done in Munich to estimate the effect running at half the normal magnetic field strength would have on the FTPCs' momentum resolution.
The tests were done comparing the momentum resolution of two venus runs produced for mock data challenge 2. MDC 2 data is not very suitable for FTPC testing as it was calculated at extremely high geant resolution, so that each track caused several hits in each padrow. However, all the available data at half field is from MDC 2.
One event of each run was processed through the fast simulation chain, assuming that the quality of ExB corrections will not change with the field strength. Fast simulation makes it possible to compare reconstructed tracks to geant tracks by simply comparing the constituent points.
The plots show the reconstructed momentum divided by the geant momentum and are in good agreement with earlier studies done with realistic simulation parameters and the measured magnet field. (Earlier simulations done by Michael Konrad assuming a perfectly uniform field looked somewhat better.) Only perfectly reconstructed tracks with 10 hits that actually belonged to the same geant track are used in the plot.
The first plot shows the resolution at full magnetic field, the second at half field. Both peaks are nicely centered around one, showing essentially correct momentum resolution, but the RMS of the distribution increases from 15 to 20 percent when going to half the magnetic field. This is in contradiction with the obvious assumption of a linear increase of the errors, which, however, is not really to be expected at closer inspection. Also, the number of properly reconstructed tracks is smaller in the second plot, but it is yet unclear if this is due to a larger range of delta spirals in the smaller field, to some other effect or just statistics.
Full field:
Half field:
The FTPC slow simulator chain:
was included in the bfc.kumac for MDC1. NO dst information was written out.
Results:
We were able to find and correct programming errors which caused NaN's.
This page was written by Janet Seyboth on February 6, 1999
In MDC2, the GEANT step size in the FTPC acceptance was reduced, so that every passing particle left a series of geant hits in every padrow. This became a serious challenge for the FTPC software and, even after optimization, increased the calculation time significantly. To get high-statistics for strangeness studies in the TPC, the planned schedule was changed in favor of more TPC fast simulator runs. Therefore, only a small number of events was run through the FTPC chain in MDC2, both with and without the slow simulator.
The complete FTPC slow simulator chain was run in the ROOT chain macro (bfc.C):
fpt - track finder
fte - track evaluator
fde - dE/dx calculator
The FTPC track, point and dE/dx information was written out to the dst by St_glb_Maker.
This page was written by Janet Seyboth on February 6, 1999
Status History for FTPC in MDC4
Chisq - determine the correct values for the $STAR/StarDb/ftpc/ftpcClusterPars.C parameters timeDiffusionErrors[1] timeDiffusionErrors[2]
This page was written by Janet Seyboth on April 27, 2001
The Distribution of the number of hits-on-global-track is NOT the same for Real Data and Simulation with Hijing through the Slow Simulator (?) What happens with all this 10-hit-on-track ? The used Gain Table is not good enough to reproduce the holes?
FTPC West | FTPC East |
AuAu minbias with low multiplicity in comparison with dAu min bias REAL DATA and SIMULATION | AuAu minbias with low multiplicity in comparison with dAu min bias REAL DATA and SIMULATION |
REAL DATA | SIMULATION |
The residuals are much better for Simulation than for Real data. We still need to do something here )-:
The trend with the variation of the number of hits on track with the multiplicity is the same for Real Data and Simulation with Hijing through the Slow Simulator
FTPC East | ||
AuAu minbias REAL DATA from Low Multiplicity (red) to High multiplicity (blue) | AuAu minbias SIMULATION from Low Multiplicity (red) to High multiplicity (blue) | |
FTPC West | ||
AuAu minbias REAL DATA from Low Multiplicity (red) to High multiplicity (blue) | AuAu minbias SIMULATION from Low Multiplicity (red) to High multiplicity (blue) |
The residuals are much better for Simulation than for Real data. We still need to do something here )-:
The FTPC fast simulator is implemented in C++ (as a part of StFtpcClusterMaker).
It was converted from Fortran (pam/ffs) to C++ by Holm Hümmler and is supported by Janet Seyboth.
StFtpcFastSimu simply takes the hit points registered by geant and turns them into FTPC points. Some cuts are applied to remove points that are outside the sensitive volume of the FTPC sectors and to account for the loss of hits due to cluster merging. Some of the geant information is kept in the gepoint table to be used in efficiency studies.
ftpcgeo.g defines the geometry for the FTPC in geant simulations. It contains information about the main aluminum cylinder, its support structures, the fieldcage and a rather detailed description of the readout chambers, and it defines the sensitive volumes.
Other geometry files of interest for the FTPC simulation are pipegeo.g for the beampipe and svttgeo.g with a description of the SVT, its support cone, the beampipe support and the shield layers.
This page was updated by Holm Hümmler on September 16, 1999