2. STAR Project Summary
Excerpted from the STAR Monthly Report for December 1996.
Project Management Summary and Highlights
The annual TAC Review of STAR was held December 9-11. The TAC stated in the closeout that "again this year...technical progress has been impressive" and that they "...remain convinced that the STAR detector can be in place and ready to do physics by the project completion date in 1999." However, they also noted that "funding resources and the schedule remain very tight," and that our "lack of on-line software leadership and group "has now reached critical significance." These are two areas that STAR Management is determined to stay on top of over the coming months and years. The final TAC Report is due out soon.The welding of the bottom 9 backlegs to the support cradles has been completed. A test roll of this portion of the magnet structure into the WAH was successful. The structure looks up to the task of supporting the entire weight of STAR.
The cable tray design and integration into the platforms and racks is progressing nicely. Tray fill factors, with all AEE and upgrade detectors accounted for, is tight but doable.
The electronics platform contract has been signed. The price is under budget! The first of several information exchange meetings with the vendor is scheduled for January 15, 1997.
TPC Summary and Highlights
The Central Membrane mounting clips have been bonded to the OFC wall and the high voltage guide tube is being prepared for bonding. The lay-up of the IFC inner skin has begun with the alignment of the inner patch (spine) strip. The electron emitter stripes for the CM have been cut and drilled. Several stripes have been pre-placed and tensioned. A second reinforcement ring has been added to make the CM symmetric and thus reduce the out of plane deflections. The laser telescope for enlarging the beam is complete and has arrived from Russia. Similarly, the numerous raft mounting parts that have been fabricated in Russia have arrived at LBNL. The PNPI (Russia) gas crew has made great strides. Sustained running at a constant pressure with full recirculation flow has been demonstrated. The east wheel (end cap) and test stand support were successfully fit up to the OFC and will be bolted to the vessel following a thorough cleaning of the mating surfaces.
Magnet Summary and Highlights
Work continued on the final RFP procurement document for the purchase of the magnet power supplies. Design was completed and checked of the main coil bumper supports that space each coil in position axially, and their fabrication will begin in January, 1997. Tooling for assembly of the magnet end rings was delivered and work has begun on design of coil installation tooling.
Electronics Summary and Highlights
Systems Test
Much cosmic ray data was taken with scintillator paddles covering a wide crossing angle range using the compact FEE card arrangement described last month. Data analysis has begun, and the first look revealed that some of the pads were being scrambled on the readout board. The entire sector was then tilted from the vertical to take cosmic ray muons with nonzero dip angle. A second drift box (for an inner sector) was fabricated. This will allow for the study of inner sector geometry with cosmic rays. System test software upgrades are continuing, and a new state manager interface is now in place.
Front End Electronics (FEE)
The 240 FEE cards arrived back from Munich. Ten were quickly tested but only seven of them worked. This yield is considerably lower than expected and will need to be watched. The readout board layout is nearing completion. The current prototype board FPGAs were modified to correct the readout ordering, and consequent pad mix up described above.
Data Acquisition (DAQ)
The fabrication of SUNNY, the prototype mezzanine card, has been delayed. It is now expected to be ready for testing by the last week in January. The ASIC has been sent to the foundry for production of sample chips. They are expected at BNL by Jan 25. The ASIC tester, unfortunately is well behind schedule and will not be ready when the sample ICs arrive. The implementation for the sector broker CPU has been chosen. DAQ will use Motorola 2604 200 MHz boards.
Trigger
The DSP production prototype is now fully loaded and ready to begin acceptance testing. The TCU board is also loaded, except for control programming, and will be set aside until March. Documentation on the CTB reviews is now available, and we expect to complete all FDR documentation soon. We expect to have a complete trigger simulation program available, including the EMC, in early 1997. Initial timing tests on simplified geometries suggest significant time saving is possible in a stripped down simulation program.
Slow Controls
The various EPICS control and monitor functions of the TPC sub-systems, i.e. HDLC link, anode wire HV, gating grid, field cage FEE pulser controls and readout board are being interfaced to a top-level EPICS controls panel.
Computing Summary and Highlights
Simulations
The geometry parser (GEANT3*) and GSTAR* are now available for use on the RHIC Pentium Pro farm. GSTAR* has been benchmarked on all available RHIC computers, PDSF, and a few machines at participating institutions. A benchmark Au+Au event (hijing, b<1fm, |eta|<4, 11950 particles total) was run through gstar with all star detectors on, all physics on, and temporary stacking. the pentium pro farm processes full au+au events with all detectors and physics on in less than 30 minutes/nt.
Analysis Software
The final version of the STAR Off-line Simulations and Analysis Software Design Document, Version 1.0, was completed. A modified version of the TPC tracking evaluation package (tte) was installed to enable "perfect" TPC track reconstruction directly from the Monte Carlo hits information. This will be used to evaluate the impact of realistic TPC tracking efficiency and performance on reconstructed physics quantities.
Software Infrastructure
Preparations were made for the Workshop on Core Off-line Software for RHIC Experiments held at LBNL on December 12-14. Presentations were made on STAF (Star Analysis Framework), STON - Star Off-line Notebook, and Event Visualization
On-line software
The Run Control environment was being set up for the system test.Zero Degree Calorimeter Workshop, February 21-22 at BNL. For further information please contact Sebastian White, BNL.
STAR Collaboration Review of DAQ. February 27-28 at BNL. For further information please contact T. Hallman, BNL.
STAR Run-Time Committee and Physics Working Group Convenors Meeting, May 20 at BNL. For further information, please contact John Harris at Yale.
STAR Physics Working Group Meetings, May 21 at BNL. For further information, please contact John Harris at Yale.
Open Discussion on STAR (Day 1) Trigger, May 22 at BNL. For further information, please contact John Harris at Yale.
BNL AGS/RHIC Users' Meeting, May 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.
Happy New Year and greetings from Long Island. January has been a mild winter month here on the Island. The only significant snowfall that we received amounted to about 6 inches (~15 cm). The snowfall came while I was out in Berkeley for the collaboration meeting so I missed it. A notable feature of the weather this month has been how often, widely, and rapidly the temperature has been changing. It goes from a high temperature of 15 F one day to 50 F the next day, then back down to the teens the next, etc.
There has been the usual steady progress at the STAR Assembly building (AB) this month, even though it was not terribly evident from the daily pictures on the Web. The test rolling of the STAR magnet steel that had been constructed through December (main magnet supports plus lower nine backleg return bars) took place right at the beginning of January. The magnet assembly was rolled back and forth between the AB and the Wide Angle Hall (WAH) a number of times. It was interesting to see that as the Hillman Rollers are made of hardened steel, and the plates that the assembly rolls on are not, that the rollers left an indented track in the steel plates. One of the primary purposes of these test rolls was to confirm what force would be necessary to push the entire STAR detector from the AB to the WAH and back. Ralph needed this information to ensure that the hydraulic jacks that will be used to push STAR are specified correctly.
A large amount of effort this month went into preparing the areas of the floor in the AB and the WAH where the seismic restraints for the STAR detector will be installed. This consisted of taking a number of cores (vertical cylinders) out of the concrete floor and cutting out some square areas around the core locations. The seismic restraints will be secured into the floor using these holes and indentations. The final six main magnet coils also arrived at the AB this month. With these six, and the four main coils and two space trim coils that were already at the AB, all coils necessary to assemble the main STAR magnet are here. The two poletip trim coils will arrive at a future date.
February should be a much more interesting month for following the construction of STAR via the pictures on the Web. The large endrings will be installed on the magnet assembly this month. This process got started on January 31st with the installation of the inner ring on the West end of the STAR solenoid. Between now and mid March all four of the endrings (two inner and two outer) will be installed, surveyed/aligned, and secured to the magnet assembly.
January also saw the RHIC collider accomplish a major milestone with the successful completion of the RHIC Sextant test. This entailed a hugh effort getting all of the necessary vacuum systems tight, getting all of the controls up and debugged, getting all of the hardware up and running, getting the sextant magnets cooled down to superconducting temperatures, and getting signed off for all of the necessary safety systems and procedures. Once this was all in hand the Gold beam was extracted from the AGS, fed through the transfer line to RHIC, fed around one of the injection arcs, threaded through the Lambertson magnet into the RHIC sextant line, and then guided around the sextant to a beam stop at the four o'clock interaction region. An interesting feature of this exercise was that RHIC has a WWW page for the Sextant test, and one could follow the daily progress of the whole procedure right down to the actual shift logs.
Pavel Nevski has joined the STAR group at BNL.
3. Notice of Meetings:
RHIC/INT Winter Workshop on Hadronic Signals of New Physics at RHIC February 20-22 at LBNL. For further information please contact Jorgen Randrup (Randrup@LBL.gov).
4. Christies Corner
5. Comings and goings at STAR
Min Nguyen has left the DAQ group at BNL for work outside of BNL.