STAR NEWSLETTER NUMBER 20

1. From the spokesman:

Reported by JOHN HARRIS

After discussions with the DOE/NP and RHIC management, I anticipate that there will be significant funding available for the additional detectors we have proposed for STAR and that NSAC and the Long Range Plan Working Group for Nuclear Physics in the U.S. have endorsed. These amount to the STAR SVT, EMC and TOF. [The STAR XTPC (as proposed outside the magnet) was designated as deferred from receiving U.S. funding, pending a new proposal and subsequent successful review.] This means that there will be money available for these detectors starting in FY96, upon successful review by the RHIC Technical Advisory Committee. It is now up to us to make sure that these subsystems are properly designed and have sufficient REAL effort to be able to propose a conceptual design and carry out the work. It is time for STAR to pull together the effort on the additional detectors as well as the effort in software for the "baseline" detector. The upcoming collaboration meeting will be a good time to aim for discussions and a report on how these efforts will be organized for the final approach towards obtaining funding. The SVT, EMC and TOF detectors are in various stages of development and we should attempt to ensure that STAR has maximum capability at start-up by making a strong push for these detectors now.

The BNL Review of RHIC Spin took place on the 5th and 6th of June at BNL. The committee consisted of world experts on spin physics. We are awaiting the formal report of the committee, but in the close-out we were told that the review was a success and that the STAR and PHENIX programs for spin physics at RHIC amounted to a world-class effort with top notch physics goals. More detailed information will be provided as we get it from the committee. I wish to congratulate Aki Yokosawa as STAR representative for RHIC Spin and thank him for his continuous efforts to promote spin physics in STAR and to represent STAR's spin physics capabilities to the community - also his hard work for the review. I wish to thank Jay Roberts, Tim Hallman and Dave Underwood for their excellent presentations, their hard work together at BNL to coordinate the information for the review during the week before the review, and for their efforts the night between the presentations and the review committee discussion session whereupon responding to my request they put together two slides summarizing the STAR measuring capabilities for spin. These two slides made the committee's job quite easy and contributed significantly to the extremely positive outcome of the review. Congratulations to all involved in the simulations effort for the review as well. Good job!

Excerpt from the STAR Monthly Report - April, 1995

A preliminary mechanical review of the central trigger barrel (CTB) hardware took place at Rice University in Houston, TX. The most significant finding at the review did not directly involve the CTB, but rather showed that the EMC was rotated 3 degrees compared to the TPC sectors and CTB modules. This is an issue for trigger and physics analysis. It will be addressed and an appropriate change will be initiated in May.

A new Conventional Systems engineer, Bruce Miller, has been hired at BNL. Bruce is scheduled to begin work May 30th. Construction of the assembly building is proceeding on schedule, and forms for the south retaining wall are being built.

TPC Summary and Highlights

Five production sectors have passed all tests. Nine sectors have been completed and an additional five sectors are in various stages of assembly.

The wheel fabrication RFQ has been issued to seven candidate vendors.

Leonid Kotchenda has returned to LBL to finish the gas system design.

The problem with the new Nd-Yag laser beam has been corrected, and a possible solution to the bowed glass mirror bundles is being tested.

Magnet Summary and Highlights

Electronics Summary and Highlights

The temporary receiver board is still in layout, and is expected to be released for fabrication in early May. The software design centered around a command interface definition is in the implementation stage. The contract for the engineering phase of the ASIC has been awarded to Albuquerque-based Innovasic, Inc. The Force Sparc 5V card was received and is being tested with Dolphin's SCI-Sbus bridge.

The VPD prototype board was laid out and is in fabrication assuming a two TDC solution. The DSM board prototype is back and under test. FPGA code as well as LUT tables are being downloaded and tested. The trigger software effort continues to concentrate on level 3, and on spin triggers at all levels. Studies of the ASIC cluster code continue, but there are no results yet.

Several meetings and telephone conferences involving the SC, DAQ, online and trigger groups were held to address the basic functionality of the STAR Experimental Control system. It was agreed that a common controls system was in the long-term interest of the experiment, and group members pledged to work towards this goal. The latest version (3.12 Beta 9) of the EPICS application software is available at Creighton and Washington.

Computing Summary and Highlights

TPC geometry namelist files were completed based on the new GEANT volume hierarchy scheme being implemented for STAR. The module that loads GEANT hit and track information into TAS tables was modified to handle overlapping events in the TPC. This module will be used in simulation and tracking studies for the RHIC p+p program. The TPC slow simulator module was upgraded to include simulations of calibration events (wire pulsing, charge injection, lasers), SCA noise, and filtered white noise for use in the summer '95 system tests. The debugging of the event reconstruction analysis chain (BFC) for multiple event processing continued with the addition of the main vertex finding module, evr.

Most of the April software design effort focused on the on-line system. The softare library effort continued to develop the AFS file system and related changes and improvements to library procedures. The analysis shell effort consisted of implementing new features afforded by the dataset library software. In addition to the on-line design effort, there was effort in preparing the documentation on the dataset library to be used in the on-line software system. There was effort on the data file manager for the transition from Informix to Oracle databases.

The second test run of the Small Prototype EMC (SPEMC) was carried out from May 1 through May 11 at the BNL-AGS B2 beam line. The major goals of this run were,

1. to test two wire chamber style shower maximum detector (SMD) technologies. One was constructed at Protvino, while the other was constructed at ANL. Data were taken both with and without a pulser used to simulate the effects of the STAR magnet on the chamber SMD performance.

2. to improve the beam line definition of pions, muons, and electrons over the full range of available momenta. Compared to the June, 1994 test run, a considerably more effective muon tag system was used which consisted of three large scintillators and two walls of Pb of 1.2 and 3.6 interaction lengths in thickness. This will allow more accurate measurements of the pi/e discrimination that can be obtained from the calorimeter and SMD information.

3. to improve the statistics for low energy pions and high energy electrons, which were studied with marginal statistics in the June 1994 test run.

Both SMDs worked very well. Clear differences in the total pulse heights in the SMDs were seen when the raw online data was gated on pion or electron beams. The positions extracted from both SMDs were nicely correlated with the beam position as measured over ~3cm areas by the ANL hodoscope. Although more refined analyses will be necessary to be certain, no significant modification of the SMD performance was seen in the data collected with the fake STAR magnet on.

The calorimeter performed exactly as expected, despite almost a year of inactivity and two cross country truck rides. The energy resolution and other calorimeter information, such as the X/Y positions and longitudinal profiles, that were obtained online were also entirely consistent with that observed in the June 1994 test run.

The results from more detailed analyses of these data will be presented at the upcoming Collaboration meeting in August.

Contribution from Lee Schroeder, LBL

JINR(Dubna) Directorate Visits BNL, RHIC, and STAR

Greetings from Long Island. Work on the STAR assembly building is progressing. The majority of the work in the WAH (chipping out the existing concrete floor and pouring a thicker one) is complete. Many of the cross supports which will hold the steel plate which STAR will roll on are in place. Part of the floor of the assembly building has been poured and the reinforcing steel has been put down in the region of the access pit for working under the detector.

The RHIC accelerator is also coming along at a brisk pace. On every trip to the tunnel I see new steps taking place in the assembly of the rings and the injection lines. The injection lines are almost complete. The transfer line from the AGS to RHIC is in the final stages of assembly and is on track for a beam test this Fall.

The STAR EMC group had a successful test beam time at the AGS this month. Please see the contribution in this newsletter by Bill Llope.

The STAR SVT had an internal review of its mechanical structures and assembly plan here at BNL on May 31st and June 1st. There was much discussion down to a very detailed level. The internal review was chaired by Bill Edwards.

7. Employment opportunities

The contract will initially be limited to two years with the possibility of an extension.

Applications, together with a curriculum vitae, a list of publications and two references, should be sent as soon as possible to

8. New STAR NOTES since the last Newsletter