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STAR Newsletter #93

June 2002
Star Home Page
Editor: Howard Matis

Contents

  1. Spokesman's Column
  2. STAR Operations
  3. STAR Council
  4. Detectors and Subsystems
  5. Period Coordinators Report
  6. Physics Working Groups (protected area)
  7. People: Comings and Goings
  8. Announcements and Notes
  9. Employment Opportunities

Spokesman's Column (Tim Hallman)

No contribution this month.

STAR Council (Jay Marx)

No contribution this month.

STAR Operations (Ralph Brown and Bill Christie)

After consulting with the STAR Sub-system managers, it was decided on May 23rd to revise the STAR shutdown plan. The primary reason for the changes adopted in the plan below is that we now know that the Photon Multiplicity Detector (PMD) will not arrive at the BNL site in early June, which the former STAR shutdown plan was predicated upon. The support structure for the PMD is currently on a boat on its way to New York. The projected arrival date for this boat into NY is June 26th. A reasonable estimate is that by the time the PMD is off loaded from the boat, cleared through customs, and trucked out to BNL, it will arrive on site sometime after the July 4th Holidays (i.e. July 8th or later). The changes proposed below are to allow the installation of the last 4 Barrel Electromagnetic Calorimeter (BEMC) modules (of the total of 60 to be in place for the upcoming run) to be done in early June, and the long process of installing the fibers on the BEMC modules to get started while we wait for the arrival of the PMD and the Endcap EMC (EEMC). We believe that getting some of this effort completed in June and early July will benefit all of the other STAR sub systems by reducing the efforts that will need resources in what are shaping up to be the very busy months of July and August.
  1. Roll the STAR detector from the WAH to the AB during the week of May 27th, and connect AC power and MCW/TPC water.
  2. Install the last four BEMC modules (from the East side of STAR) to complete the West BEMC barrel during the week of June 3rd.
  3. Move to the West side of STAR, and start installing the fibers on the 36 BEMC modules installed this year, starting the week of June 10th. Continue this fiber installation until the PMD and EEMC have arrived at the BNL site. This is contingent on the availability of the fibers for the BEMC modules. Our current understanding is that we can plan to have available in June (phased delivery) enough fibers for ten of the BEMC modules.
  4. Rolling the STAR detector from the AB to the WAH, to allow placing the EEMC and PMD materials into the WAH when both are available on site. As pointed out earlier, it appears that this would happen sometime during the week of July 8th, but hopefully not later than early the week of July 15th. It is estimated that this process (disconnect, roll to WAH, rig in PMD and EEMC, roll to AB, and reconnect power and water) will take less than one week.
  5. Immediately after placing the PMD and the EEMC in the WAH, rolling the STAR detector back to the AB, reconnecting the AC power and MCW/TPC water, and continuing with the BEMC fiber installation effort until completed.
  6. If the RICH is going back into the STAR detector, it would have to be installed into the magnet from the East side as soon as the STAR detector is back in the AB, prior to assembly of the SVT/SSD installation platform on the East side of STAR.
  7. Work on the installation of the SVT/SSD on the cone, and insertion of the cone on the East side is a continuous effort and must wait until after roll-in of the STAR detector for the delivery of the PMD and EEMC into the WAH. The SVT/SSD installation must begin no later than August 1st.
  8. With the STAR detector in the AB we are back on schedule with the West BEMC fibering effort and in parallel installing the SVT/SSD on the East side, and the PMD and lower EEMC in the WAH.

Detectors and Subsystems

FTPC (from Volker Eckardt)

We recently replaced 24 bad FEE boards on the second FTPC. Now both chambers are ready for their reinstallation in September. An automatic switchover unit is in place for the CO2 gas supply, while the drift velocity monitor is in its final position. Work on tuning the different analysis programs is still going on. For a more reliable deconvolution, the cluster finder was modified and is now in better agreement with simulations. Also the tracker was further improved. After some small corrections to the coordinate systems, the reconstructed vertices from the FTPCs and the TPC are within a millimeter of each other. We hope to be ready for a production run in the next few days.

Slow Controls (from Mike Cherney)

Work continues on the upgrade of the BEMC controls. Hardware has been obtained for the EEMC. Software for the EEMC has been defined. Operation of MEDM on a laptop (without a Sun workstation) has been demonstrated, but conflicts between software versions have limited its development.

EMC (from Alexandre Suaide)

No contribution this month.

TPC (from Blair Stringfellow)

No contribution this month

Level 3 Trigger (from the commissioning contingent)

No contribution this month.

Endcap EMC (from Will Jacobs)

The Endcap lower half backplate and hub structure are in house at IUCF. They are shown mounted on the strongback in the accompanying photo, shortly after layer #23 radiator plate was fit and attached to the hub. Mounting of the remaining layers (1 to 23 are already fabricated) is in progress. Also in the photo, the vacuum lifter for manipulating the plates is shown as it is being maneuvered away by a technician. As a backdrop, the first prototype radiator assembly can be seen, supported by its keyed stainless steel ring, on a support stand against the wall.

Endcap lower half backplate and hub structure

Photon Multiplicity Detector (Subhasis Chattopadhyay)

Fabrication of unit modules for PMD are in progress at Calcutta, Jammu and Bhubaneswar in India. The PMD will have 142 of these unit modules. 100 such modules are complete in all respects and tested. Assembly of first supermodule containing 9 unit module is in progress and will be tested at CERN, starting on June 17, using the PS pion and electron beams. Components of an unit module including the readout board before assembly are shown below.

Unit Modlule of a PMD

The support structure for PMD has been despatched from Calcutta to Brookhaven by sea and is scheduled to reach BNL around end of June. This structure consists of the hanging arrangement of the PMD and the motorized system for the movement of the detector.

Assembly of 2000 readout boards using 8000 GASSIPLEX chips will start on June 20. After mounting the prototype boards on a unit module, they were carefully tested with cosmic rays. A significant amount of work have been completed on the implementation of the PMD in STAR-DAQ. A detailed PMD status report will be presented at the next collaboration meeting.

RICH

No contribution this month.

TOFp - (Bill Llope and Frank Geurts )

During the last 3 months the analysis of the TOFp/pVPD system has made solid progress. The pVPD resolution with preliminary offline corrections is ~50 ps in central collisions. After cleaning up known problem areas in the corrections, we may get to perhaps 40-43 ps on the start side. With preliminary stop-side corrections, the total time resolution per slat (TOFp has 41 slats) can go as low as 80 ps for the central slats. This is well below the ~100 ps design specification for the system. At this point in the analysis, approximately 2/3 of the slats have a time resolution, after corrections, which is below or at the design value. More work is needed to understand some calibration issues in the low-eta region of the detector. An abstract for a poster on the TOFp/pVPD system has been accepted for QM02. The technical aspects of the system and the latest results of the full energy Au+Au analyses will be discussed. Analyses of the p+p and ~20 GeV/c Au+Au data are also in progress but won't be on the poster.

In the first week of June, the TOFp tray was pulled out of the STAR detector and is now stored in the clean room. At the end of June, we will open up the tray for maintenance work - replacing 3 HV cells and 1 FEE board. Also, we will implement a retrofit to the PMT wrapping to suppress the ~1/month cell failures seen in the last run.

At the AGS near E949, the TOFr tray is still under test. This TOF system is another modified CTB tray but it contains 192 channels of MRPC detectors of which 180 are actually wired to FEE cards. We expect to read out 72 of those channels. TOFr has been approved for installation in STAR in advance of the next run. The AGS tests of TOFr focus on establishing the optimal running conditions for the best time resolution. High voltage scans, discriminator thresholds, and different gas mixtures are under study. Over the last three months the system has been very robust showing only a few HV trips (which may have been due to the supply and not TOFr) and no FEE problems at all. Analysis of the test data is underway, but preliminary results look very encouraging. Once the AGS SEB program ends, the test experiment will be disassembled and the TOFr tray will be moved to the clean room, next to her older brother TOFp.

Period Coordinator Reports

Physics Working Groups - (See the protected area)

This section contains summaries of the status of the physics working groups. These articles are in a protected area for STAR collaboration members only. This link uses the standard STAR account and password for physics results. If you do not have this information, please contact your council representative.

Go to this month's articles

People

Announcements and Notes

Employment Opportunities

Postdoc/Junior Faculty Position (Creighton University)

The Creighton University RHIC physics group anticipates at least one opening at the postdoc or junior faculty level. Interested persons should contact Michael Cherney (mcherney@creighton.edu) or Janet Seger (jseger@creighton.edu). The formal announcement should appear in a subsequent newsletter.

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