Relativistic Heavy Ion Collider (RHIC)

1. IMPLEMENTATION OF SOFTWARE INPUT OUTPUT CONTROLLERS FOR THE STAR EXPERIMENTJ. M. Burns, M. Cherney*, J. Fujita*Creighton University, Department of Physics, Omaha, NE

2. Relativistic Heavy Ion Collider (RHIC) • Located at Brookhaven National Laboratory (BNL) on Long Island, New York. STAR • Collide gold-gold nuclei in order to study nuclear matter created in a hot, dense state like that of the earliest stages of the Big Bang.

3. STAR Experiment • STAR (Solenoidal Tracker at RHIC) • location of relativistic heavy ion collisions • consists of several detectors for tracking and studying large numbers of charged particles emerging from collisions • slow controls and collision data analysis

4. Upgrade of Hardware Controls • PC-based front end processors for new subsystems with high memory capability • system upgraded to Linux compilable new versions of the real-time operating system • phasing out Sun workstations to those running Linux for the new and upgraded subsystems Original Configuration of Hardware Controls • 10-year-old specialized front end processors for detector control with low memory capability • front end cards housed in crates • ~30 specialized processors running an old version of the real-time operating system • startup files are downloaded over Ethernet from a single Sun host workstation

5. Original Configuration of Hardware Controls Some specialized processors use program code that is incompatible with newer versions of real-time operating system. Most workstations open user interfaces for the control and monitoring of the experiment. Data for the user interface is received from local Ethernet broadcasts. Upgrade of Hardware Controls Existing subsystems using serial interfaces are being moved to the PC-based system. Program code compatible with newer versions of real-time operating system is available locally on the PC processors. Program code for the specialized processors is downloaded from a Linux workstation. Continue using same user interfaces. Data still received from local Ethernet.

6. EPICS • Experimental Physics & Industrial Control System • a set of open source software tools • developed collaboratively • framework for creating alarms, archives, control panels, displays, etc.

7. Soft IOC • Software Input Output Controller • replaces specialized processor card that served as a hardware IOC • Soft IOC’s are run on PC’s with Linux operating systems

8. Again, Why Upgrade? • processor cost • easily maintained • higher memory capability • faster processing speed • multiple applications on one PC

9. Slow Control Projects • Temperature and Humidity Monitors • Ground Integrity Device • TPC FTPC Gas Systems • Detector Control Bits Application

10. Temperature and Humidity Monitors • monitors temperature and dew point throughout the experimental area • dew point should always be lower than the cooling water temperature • Hygrometer • PC interface • Old Processor

11. Ground Integrity Detector (GID) • reads current • detects deviations between experiment ground and earth ground • experiment ground is the basis of signal size measurements of the experiment • signal size is necessary for determining the energy deposited by the particle in the detector

12. GID Project • originally monitored by log entry periodically throughout the day • GID is located in experiment hall • connected to a PC placed within the Data Acquisition (DAQ) Room by cable • PC connected to local network • makes it possible for GID readings to be directly monitored and archived in the main controls room

13. GID DAQ Room Control Room

14. Upgrade of GID • GID raw data output: Original DataFormatted Data • use data sorting software written in C++ to format input data

15. Upgrade of GID • PC connected to local network by Ethernet • data is broadcast, then accessed and monitored in the main control room by the user interface

16. Why Upgrade the GID? • make GID monitoring easily accessible • better isolate and quickly fix problems with experiment since GID data is archived • model for other control system upgrades for STAR

17. TPC & FTPC • TPC (Time Projection Chamber) & FTPC (Forward Time Projection Chamber) gas systems regulate a mixture of gases at a certain temperature & pressure to the TPC and FTPC. • an alarm & interlock system separate from data acquisition/control system prevents TPC/FTPC from operating under unsafe conditions • gas systems parameters archived & purification of recirculating gas mixture is controlled by computer data acquisition/control system

18. Current Monitoring/Control System • ASCII files are run through sequencer on a specialized processor located on platform for reformatting and then sent back to computer in control room for archiving, monitoring, and controlling. • Gas systems at STAR stream data into ASCII files which are sent to a processor located in STAR control room.

19. Upgraded TPC/FTPC Monitoring/Control System • SED (Stream EDitor) reformats ASCII files saved by monitoring systems & declares new variables for each gas subsystem (so new system for monitoring/control runs in parallel with existing monitoring/control system) • gas monitoring systems save data to Linux processor running EPICS located in STAR control room on which reformatting & processing takes place

20. Upgraded TPC/FTPC Monitoring/Control System • data is read, reformatted, and sent to the database every minute FTPC Gas System formatting of ASCII file and final output of ASCII file data

21. TPC/FTPC Gas Monitoring • database outputs data to an archive and user interface on a STAR control room computer User interfaces for TPC and FTPC gas systems monitoring.

22. Detector Control Bits • determines which part of the experiment’s alarm system is active • allows operator to enable and disable the subdetectors which are in use • upgrade was relocation of systems to user PC’s running Linux

23. Acknowledgments • Brookhaven National Laboratory • United States Department of Energy • Ferlic Undergraduate Research Scholarship • Creighton University High Energy Physics Group