2. STAR Project Summary
Excerpted from the STAR Monthly Report for March 1997.
Project Management Summary and Highlights
The Magnet assembly process reached a milestone this month - 15 of 30 backlegs have been installed. The next step is to begin coil installation. The TPC also made good progress this month in getting ready for Cosmic Ray testing. The IFC is nearly complete and the clean tent surrounding the TPC has been erected. The Electronics System Test also made the jump from being able to read out data from several hundred channels to close to 2500 channels. Everything is working smoothly thus far.As reported in conventional systems and integration, there will be an Electrical Safety Review of STAR on April 22nd. This review, by the RHIC ESC, is the first of probably 2 reviews covering everything from the AC power to Front End Electronics cards, power supplies, cables, etc.
Also in April, there will be a working meeting (a finalizing design and decision making meeting) at ANL on the Barrel EMC Support System. The intent is to finalize the remaining design and manufacturing decisions so that supports can go out for bid and begin being manufactured.
TPC Summary and Highlights
The IFC fabrication is nearing completion. All of the outer skin electrodes strips are bonded to the core thus completing the basic sandwich composite cylinder. Fabrication of the resistor chain covers has begun. A production laser raft cover has been assembled and is ready for installation. The gas pad for the liquefied inert gas and methane gas has been completed and the installation of the gas supply system has begun. The "clean" enclosures at either end of the TPC have been erected and cleaned. A HEPA filtration system has been installed and scaffolding has been assembled in the east tent. With the exception of some last minute modifications the enclosures are ready for the "in-bore" assembly work.
Magnet Summary and Highlights
The order for the Pole Tip Trim Coils was initiated with Contracts & Procurement and the request for bids is out to vendors. All proposed bids have been evaluated for the procurement of the Magnet Power Supply and its contract should be awarded in early April. Design of coil lifting fixtures is complete and out for fabrication and delivery is expected in mid-April. The main Detector Hydraulic Drive System contract was awarded and delivery is scheduled for July. Delivery of the Pole Tips from PCC has hit a transportation snag and will push delivery into late April, 1997.
Electronics Summary and Highlights
Systems Test
In March, the system test expanded from one to four readout boards covering a major fraction of a sector. The entire inner and outer sectors were instrumented with FEE cards and (newly produced) cables. Readout board cooling manifolds were installed and connected to a chiller that was almost operational as of March 30th. Four readout board main boards, each reading out 20 FEE cards, were installed and connected to four Rosie boards. Mini-DAQ was expanded to read out these 80 FEE cards successfully; and geometry, data and pulser events were read out. Production FEE power supplies were used to power the readout boards. Geometry events are also read out completely correct.
Front End Electronics (FEE)
The second readout board prototypes are almost completely debugged, and are being used in the system test. Four boards are operational, and two are very close to being completely assembled. The design of the readout board plug-in expansion cards is well underway with the schematic complete and the layout in progress.Two power supply chassis, each holding 3 power supplies (one supply powers 1 readout board), were completed, tested and are installed in the system test. The rack-mount chassis include supplies and facilities for current monitoring and computer control.
The orders for the full production of SCA and SAS chips are now at Orbit, and fabrication has begun. They should arrive here in late April or early May.
Data Acquisition (DAQ)
Testing of the ASIC is taking much longer than expected because problems continue to be discovered related to the tester board and/or thermal-induced behavior. Testing is now scheduled to be complete by April 15.Sunny, the prototype mezzanine card missing only the ASICs, should be debugged by mid-April.
The prototype, high-speed, data distribution circuitry is in layout. This is the fiber-to-mezzanine card delivery system with all the features to be used on the final receiver card.
Trigger
DSM and TCU test procedures are nearly finalized. DSM loading and simple testing continues at a low level. The MWC FEE test using the Dorfan chip uncovered a possible problem with the gain for negative signals and the noise immunity of the board design. Investigation of this problem will continue so that single wire hit counting on the MWPC can be done. The 10 CTB trays for the LBNL cosmic ray test are nearly ready to ship from Rice.In software we have converted all of our event files into xdf format and have tape archived the older data sets. The rlo package in GSTAR is re-implemented as hit counting for the MWC. WWW documentation on the STAF packages for trigger has been brought up to date.
Slow Controls
The control and monitoring of the TPC low voltage power supplies from an EPICS display screen has been tested and verified using six power supply units. The control panel further provides for the turning on/off of groups of power supplies (e.g. in a given rack).The issue of how to pass TPC gas data from a PC (Windows 95) to an EPICS database residing on the VME167 is currently being addressed.
The EPICS GPIB drivers for the Keithley K7001 switch system and K2001 digital are functioning after the vwWorks kernel was rebuilt. However, it was found that when used in conjunction with other certain VME interface boards, Direct Memory Access errors are generated; the cause of this interference is being investigated. A new EPICS device support module was also written to handle commands for the K2001.
Computing Summary and Highlights
Simulations
Concentrated efforts are underway to understand the accuracy of GEANT's description of low energy particle interactions, and the effects that various beam-pipe designs have on the SVT, TPC, and FTPC tracking performance. The default GEANT thresholds in GSTAR were lowered from 10 MeV to 1 MeV which modifies the appearance of the effects from low energy particles and necessitates the reinvestigation of the effects of the beam-pipe. This work will be summarized in a presentation to the Technical Committee on April 22nd.Several new packages were proposed and approved: a) /sim/crs which generates cosmic ray events using HEMISCOM for the cosmic ray tests, and b) /sim/tdi which is designed for the cosmic ray tests of the TPC.
Bugs were found and fixed in both the TPC slow simulator and TPC fast simulator. Changes for star_arch = sun4os5pc were implemented in the CERN Libraries. The new CERN libs were installed, and GSTAR and g2t binaries were remade for this platform. A bug in GSTAR leading to particle loss when using the 'PHASESPACE' or 'MOMENTUMBIN' (internal) event generators was fixed. A bug in g2t that could lead to g2t crashes on the Pentium Pro machines was fixed.
Analysis Software
Forward TPC tracking studies for several beam pipe design options were completed by the FTPC software group. The results indicate a 5% improvement in tracking efficiency in going from the standard Be-steel design to an all Be pipe.Electric field distortion effects on TPC space point positions due to a shorted stripe were simulated; a blind tracking analysis using simulated straight tracks was able to correctly deduce the source of distortions.
The first iteration of software was finished for pedestal subtraction, zero suppression and gain correction which will run on-line in the TPC cosmic ray tests.
A preliminary study was completed to determine the particle identification capability of the FTPC using dE/dx.
A significant portion of the former Big Full Chain (from TAS) is now running in STAF. This software has been used for K0-short reconstruction analyses.
An html version of the STAR Off-line Software Design Document Version 1.0 was installed on the World Wide Web under the SAS home page.
Software Infrastructure
Preparations were made for the SL97a release of the library including code improvements and documentation. Effort also went into developing a common framework for off-line RHIC software in collaboration with members of PHENIX. Significant work was also performed on the interface between STAF and ROOT.
On-line software
On-line software focussed on the run control for the TPC cosmic ray test. Additionally, discussions were held concerning how to include slow controls information into the acquisition system so that information about the detector hardware parameters can be included in the analysis of the cosmic ray data.STAR Physics Working Group Meetings, May 20 at BNL. For further information, please contact John Harris at Yale.
Open Discussion on STAR (Day 1) Trigger, May 21 at BNL. For further information, please contact John Harris at Yale.
BNL AGS/RHIC Users' Meeting, May 22 & 23 at BNL. For further information, please contact Bill Christie at BNL.
STAR Collaboration Meeting, July 20 - 26, at BNL. For further information, please contact John Harris at Yale.
Greetings from Long Island. April has been a generally mild month here on Long Island. With Spring upon us we're starting to have days with temperatures up into the low 70 F range. All of the Daffodils and Tulips are in full bloom. The Magnolia and Cherry blossom trees have bloomed and are already losing their flowers. The buds are rapidly developing on all of the deciduous trees, the Azaleas are close to opening, and it's the start of the short period of time during the year when my lawn actually looks OK. Spring on Long Island is beautiful.
As you've probably noticed via the pictures on the WWW, the part of the STAR magnet that has been assembled so far got painted this month. The fifteen backleg return bars that one still sees stacked on the floor of the Assembly building will be painted as they are installed. Also noticeable via the web pictures this month has been the installation of the Air Conditioning system in the Assembly building (AB). The Air handling units can be seen in the upper left and right corners of the AB picture. The installation of the seismic restraints in the Wide angle hall and the AB is just about complete.
This month the installation of the main and space trim coils of the STAR magnet will begin. The installation of the coils will start in about two weeks and continue for a period of approximately two months. By the time of the STAR collaboration meeting here at BNL all of these coils should be in place. Just in time for a tour.
There are a number of meetings coming up here at BNL this month (please see Notice of upcoming meetings in this issue). In addition to the STAR meetings there will be the annual AGS/RHIC Users meeting on May 22nd and 23rd. From the agenda it looks to be an interesting meeting.
3. Notice of Meetings:
STAR Run-Time Committee and Physics Working Group Convenors Meeting, May 19 at BNL. For further information, please contact John Harris at Yale.
4. Christies Corner
5. Comings and goings at STAR
Akio Ogawa has joined the Penn St. group and will be resident at BNL.