This page is the dictionary for the abbreviations, acronyms and other vernacular
commonly used in discussions about the TOFp Systems.
A
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- ADC
- Analog to Digital Converter. These integrate the current pulses
out of the PMT (buffered and driven over long cables by the FEE boards) and
provide to the CAMAC backplane digital numbers proportional to the total area
of the PMT pulse in pC. This number is related to the energy deposited in the Slat
by the particle following a number of software calibrations for experimental
effects. The ADCs are LeCroy 2249A 12ch CAMAC units obtained from HEEP. For
the detailed manufacturer information, go to the Module
Full List. Additional information is on the TOFp CAMAC Crate
map page.
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B
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- BiRa
- Abbreviated name for the BiRa Model 2601 CAMAC I/O module that is
used as part of the communication with the STAR Trigger to obtain the trigger
word and token information for use by the TOFp Local DAQ and Local Trigger.
- Boat
- The welded aluminum pieces that connect the pVPD Front and
Back Plates and provide the mounting point for pVPD Detector Assemblies.
- Base Plate
- A pVPD Assembly mounts off of the beam support I-beam
in a clam-shell design - the Base Plate attaches to the I-beam and is the "lower shell",
and the Upper Structure rests on the Base Plate from above and is the "upper shell".
The Base Plate also provides the mounting location of the FEE box.
The Base Plate is electrically isolated from the pVPD Detector Assemblies and
from the FEE box, as both the I-beam and Base Plate are at Balcony (i.e. BAD) ground.
C
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- CTB
- Central Trigger Barrel. This system exists in STAR at the
same cylindrical radius as the TOFp Tray, and provides using much bigger slats
fast multiplicity information to the STAR Level-0 trigger. The TOFp Tray is the
same overall construction and dimensions as the trays containing CTB detectors.
- CTB 1440
- The high voltage needed by the pVPD Detector Assemblies is
provided by same the LeCroy 1440-series High Voltage mainframe that provides
the high voltage for the STAR CTB detectors. The pVPD High Voltage settings
are thus controlled from the STAR Control room using the same GUI used to control
the CTB high voltages.
- Cell
- Abbreviated name for HVSys Cell, the Cockroft-Walton style
PMT base used to generate and monitor the PMT high voltages in the TOFp Tray.
- Control PC
- The 600MHz P-III Coppermine PC running Linux in the STAR
Control Room. This machine is used for specific control functions, and all system
health and raw data monitoring.
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D
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- DAQ PC
- The 500 MHz Pentium-III Linux computer mounted in Rack 1B-1, South
Platform. This machine runs the TOFp DAQ software that reads the ADCs, TDCs, and A/D
in the TOFp CAMAC Crate, and interacts with the STAR
Trigger and STAR DAQ Systems via the BiRa and fiber-optics, respectively.
There is a serial cable connection between the DAQ PC and the HVSys System Module, so
the DAQ PC is the machine that supports terminal connections ("minicom") with the HVSys
for control and monitoring the high voltages used in the TOFp Tray.
- Detector Channel Number
- a.k.a. detector Location Index. A number specifying
a specific location of an active detector element in either the TOFp tray (start detector)
or the pVPDs (stop detectors). The TOFp Detector Channel Numbers run from 1 (upper
left in top view, eta~0 row) to 41 (lower right, eta~1 row). The pVPD Detector Channel
Numbers are 1-3 on the East pVPD and 4-6 on the West pVPD. pVPD Detector Channels 1 and
4 are at 12 o'clock when looking along the pipe from STAR Z=0, and the channel numbers
increase clockwise on each side from this viewpoint. See the TOFp
maps page and the pVPD maps page.
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E
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F
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- FEE
- Acronym for Front End Electronics.
- Front End Electronics
- Custom circuits that are positioned close to active
detector elements and are compact and very fast leading-edge discriminators. The same
boards are used inside the TOFp tray (10 boards, 41 active channels total) and on
both the pVPDs (2 boards, 6 active channels total, half on each side of STAR)
- Foam
- The structural element that holds each row of TOFp Slats at the
proper position and angle w.r.t. the bottom of the Tray.
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G
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- Grounding
- The local ground levels used in the TOFp Tray and at each
pVPD FEE box are obtained by direct connection to the Platform in Rack 1B-2. Dirty
grounds exist near the TOFp System only near the pVPD Detectors. At these locations,
the Aluminum I-beam and pVPD Mount Baseplate are at the Balcony (i.e. BAD) ground.
The pVPD FEE box and its contents are electrically isolated from this ground. The local
ground here is obtained from a conductor in the pVPD LV Bus.
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H
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- HVSys
- The generic name of the system used to control and monitor
the high voltages used to power each of the 41 PMTs in the TOFp Tray. STAR-specific map information
is on the HVSys maps page (Run 2,
Run 3, before 1/30/03,
Run 3, after 1/30/03)
and the operating information
is on the HVSys User's Manual.
The HVSys consists of the HVSys System
Module, the HVSys Bus cable, and 41 HVSys Cells daisy-chained on the Bus cable inside the TOFp Tray.
- HVSys Bus
- The 10 conductor, 300V/1.5A rated ribon cable that connects each Cell
to the System Module.
- HVSys Cell
- The small Cockroft-Walton style base that attaches to each PMT, to the
HVSys Bus, and to the FEE via an RG-174 coaxial signal cable. Each Cell has a unique ID that is
recognized by the System Module. The map of the Cell locations inside the TOFp Tray is
on the HVSys maps page.
- HVSys System Module
- The electronic power supply for the HVSys in the shape of
a 6-U VME module, that is mounted to a 2U wide rack panel in the TOFp
Rack.
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I
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J
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K
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L
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- LV
- The generic term for the systems providing the +5V and -5.2V power
needed by the FEE used on-detector in the TOFp Tray and pVPDs.
- LV Bus
- Context-dependent name of the cable that connects a Low Voltage
Supply in Rack 1B-2 to either the TOFp Tray feedthrough plate or one of the two
pVPD FEE boxes. There is thus one TOFp LV Bus, one pVPD East LV Bus, and one pVPD West
LV Bus. These cables are identical in construction and length. Each consists of 5
conductor, 10 AWG
VNTC wire, terminated at the detector side with Amphenol Circular Plastic Connectors
with 35A per contact-rated pins/sockets. Termination at the supply side is directly
to terminals on the back of the power supplies in Rack 1B-2. The 5 conductors in
each bus correspond to +5V supply, +5V return, -5.2V supply, -5.2V return, and Platform
Ground. The voltage levels applied at the power supply side exceed those at the
detector side, due to the voltage drop along the LV Bus that is related to
current draw of the FEE on that bus. There are 10 FEE boards drawing current on
the TOFp LV Bus, and 1 FEE board drawing current on each of the two pVPD LV Buses.
- Local DAQ
- The generic name for the components installed in Racks 1B-1 and 1B-2
that serve to extract digital raw data from the CAMAC crate and present these data to
the STAR DAQ including the appropriate interactions with the STAR Trigger.
This system consists of the DAQ PC, which reads the TOFp CAMAC crate, and the software running on
the DAQ PC that coordinates the local actions (interaction w/ Local Trigger, CAMAC reads)
and the communication of STAR Trigger information to the TOFp System and the TOFp raw data
to the STAR DAQ.
- Local Trigger
- This is a fully NIM logic system located in NIM Bin #2 in
Rack 1B-2 that generates the master start signals and gates for the TOFp ADCs and TDCs
based upon the pVPD timing information, interacts directly with STAR Trigger, and
controls the busy logic and interrupts. A detailed text description of the Local
Trigger is here. For the component location and manufacturer's
information see the TOFp NIM Bin #2 map.
- Location Index
- a.k.a. Detector Channel Number. A number specifying
a specific location of an active detector element in either the TOFp tray (start detector)
or the pVPDs (stop detectors). The TOFp Detector Channel Numbers run from 1 (upper
left in top view, eta~0 row) to 41 (lower right, eta~1 row). The pVPD Detector Channel
Numbers are 1-3 on the East pVPD and 4-6 on the West pVPD. pVPD Detector Channels 1 and
4 are at 12 o'clock when looking along the pipe from STAR Z=0, and the channel numbers
increase clockwise on each side from this viewpoint. See the TOFp
maps page and the pVPD maps page.
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M
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N
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- NPS
- Acronym for Network Power Switch
- Network Power Switch
- Commercial unit that allows remote control via ethernet of
eight US-standard three-prong AC power jacks, from which various components in the
TOFp Rack draw their AC power. STAR-specific map information
is on the NPS maps page.
O
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P
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- PMT
- Acronym for Photomultiplier Tube. The optical transducer attached
to a each scintillator in either the TOFp Tray or the pVPD. These devices
convert a fraction of the incident scintillation light into a current pulse
that is input to the on-detector FEE. In the TOFp Systems, there are 41 Hamamatsu
R5946 Proximity Mesh Dynode PMTs in the TOFp Tray, and 3 Hamamatsu R2083 PMTs
in each of the two pVPDs (6 total).
- pVPD
- Acronym for Pseudo Vertex Position Detector.
- Pseudo Vertex Position Detector
- A detector subsystem of the TOFp System.
The subsystem consists of two identical mechanical structures which mount near
the beam pipe outside the STAR pole tips, one on each side of STAR at the same |Z| position.
These are the start detectors for the TOFp System.
- pVPD Assembly
- One of the two identical structures one each side of STAR
near the beam-support I-beam. A pVPD Assembly includes a mechanical support structure made
out of Alumimum and Delrin, Three (3) pVPD Detector Assemblies, and a FEE box.
- pVPD Detector Assembly
- The active element on the pVPD. These are
cylindrical black steel tubes mounted off of the mechanical support structure of a pVPD
Assembly. There are Three (3) pVPD Detector Assemblies per pVPD Assembly. Each cylinder
is a 7-layer magnetic shield that contains (listed front to back) a ~2" air gap, a Pb
layer, a layer of BC420 plastic scintillator, a Hamamatsu R2083 PMT, and a HV Base.
Each pVPD Detector Assembly weighs approximately ten pounds. These contain PMTs and
electronics and are thus fragile.
Q
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R
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- Remote Threshold System
- See Threshold System.
- Row
- Typically abbreviation for Slat Row.
S
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- Slat
- The active element in the TOFp Tray. There are 41 of these, and each
is Bicron BC420 plastic scintillator with diamond milled edges and dimensions 1.5" x 2cm x 20cm.
- Slat Assembly
- A single unit of active element, the Slat, plus a PMT and a Cockroft-Walton
Base. The Slat is wrapped in two layers of unpainted low-fibrosity Tyvek for reflectivity and
one layer of black photographers plastic for light-tightness. An optical fiber pigtail is
attached to each Slat Assy and routes through the Tyvek and Plastic wrapping to allow
laser pulse input for testing and maintenance purposes.
- Slat Row
- In the TOFp tray, the 41 Slat Assemblies
are arranged in ten rows, where in each row the 1.5"-wide axes of each Slat are coplanar
and positioned at a fixed position and angle w.r.t. the Tray. Row 1 is that closest to
eta=0 and consists of 5 Slat Assemblies side-by-side. Rows 2 through 10 each consist of
4 Slat Assemblies side-by-side, and Row 10 is near eta~1. The mechanical stops used to
insure the Slats in each Row are parallel and square to each other are custom shaped
pieces of Foam permanently affixed to the Tray body.
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T
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- TDC
- Time to Digital Converter. These measure the time difference
between a master start signal derived from the pVPD signals and stop signals
from individual active detectors (41 TOFp and 6 pVPD) in the system.
They provide to the CAMAC backplane digital numbers proportional to this time
difference in units w/ the LSB of 50 ps. The TDCs are LeCroy 2228A 8ch CAMAC units obtained from HEEP. For
the detailed manufacturer information, go to the Module
Full List. Additional information is on the TOFp CAMAC Crate
map page.
- TOFp
- Acronym for Time Of Flight Patch
- TOFp Systems
- Top level name of the entire complement of detector and electronics
systems, which includes the TOFp Tray, two additional detectors called pVPDs, rack equipment,
cabling, computing, and software.
- TOFp Tray
- The "stop" detector. This is a 50mil-walled welded alumimum box, of
the same dimensions as the STAR CTB trays, which contains 41 Slat Assemblies, 10 FEE
boards, 1 Threshold Interface Board, as well as water cooling and internal temperature
monitoring.
- Threshold System
- a.k.a. Remote Threshold System. This system
consists of the Threshold Control Panel in Rack 1B-2, the cabling to three detectors
(1 TOFp tray, and 2 pVPDs) each called a Threshold Bus, and the Threshold Interface Board
at the three separately-located detector sides. This system uses a 4-20mA control loop
to result in a precise, remotely-controllable, low-voltage level that is used as the leading-edge
threshold on the FEE boards attached to each TOFp or pVPD detector channel. For additional detailed
information on the Threshold System see the TOFp Rack map
and the Threshold System Description.
- Threshold Control Panel
- This is a 4U-tall 19"-rack unit in Rack 1B-2. The
front panel contains 5 digit numerical LED displays, switches, and dials that are used
to read and display six numbers: the setpoint and read-back value for the remote
thresholds generated for the FEE at the detector side for the 1 TOFp Tray and the 2 pVPDs.
- Threshold Bus
- The generic name for the 6 conductor cable used to connect
the Threshold Control Panel (platform) to a Threshold Interface Board (detector). There are
thus three Threshold Buses in the TOFp System, one for the TOFp tray and one each for the
two pVPDs, and these are identical in terms of construction
and length. The voltages and currents on these buses are negligible.
- Threshold Interface Board
- The remote component of the Remote Threshold System. There are
three of these, one each at each detector (1 TOFp tray, and 2 pVPDs). The Threshold Interface
Board draws the low voltage it needs to operate from the LV Bus powering the nearby FEE.
These boards provide
the precise, remotely-controllable, low-voltage level that is used as the leading-edge threshold
on the FEE boards.
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U
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- Upper Structure
- A pVPD Assembly mounts off of the beam support I-beam
in a clam-shell design - the Base Plate attaches to the I-beam and is the "lower shell",
and the Upper Structure rests on the Base Plate from above and is the "upper shell". The
Three (3) pVPD Detector Assemblies mount to aluminum Boats that are mechanically part
of the Upper Structure.
V
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X
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Y
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Z
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- Z
- The coordinate in the STAR global coordinate system that measures
the distance along the central axis of STAR (i.e. along the beam pipe). The
pVPDs are at a STAR |Z| position of ~4.3m.
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0 - 9
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These are the most commonly-spoken numerical abbreviations for specific commercial units used in the TOFp
System. For any site-specific and/or manufacturer information on these (and others), see the
Module Full List or the TOFp Rack map.
- 380A
- LeCroy 32 ch Multiplicity Unit. (Tray hit multiplicity/event information).
- 706
- Phillips Scientific 16 channel NIM discriminator, every other input open.
(Platform rediscrimination of TOFp and pVPD timing signals. Input to Local Trigger as
raw starts).
- 1992
- Kinetics Thermocouple Termination Panel. (Thermocouple termination and
reference thermocouple for input into 3516).
- 2083
- Hamamatsu 2" PMT. (Optical transducer for the pVPDs).
- 3516
- Kinetics 32 channel, 12 bit Scanning A/D CAMAC module. (Thermocouple and
remote threshold digitization).
- 5946
- Hamamatsu Proximity Mesh Dynode PMT. (Optical transducer in the TOFp Tray).
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