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Slow control for Compass Saclay chambers. Françoise Gougnaud. Micromegas & drift chambers. Main goal. Main goal : a measurement of the gluon spin contribution to the nucleon spin Beam of polarized muons on a target of polarized nucleons (protons).
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Slow control for Compass Saclay chambers Françoise Gougnaud
Micromegas & drift chambers
Main goal • Main goal : a measurement of the gluon spin contribution to the nucleon spin • Beam of polarized muons on a target of polarized nucleons (protons)
2002: 12 MICROMEGAS (MICRO MEsh GASeous) chambers and 3 Drift chambers installed
Slow control forHigh Voltages and Thresholds • High Voltages : CAEN system SY127 • Thresholds for Micromegas chambers chip SFE16 : a Front End BiCMOS ASIC dedicated to the Read-out Micromegas 24 busses x 32 SFE16 x 4 registers • Thresholds for 3 Drift chambers 1 threshold by plane of detection :8 channels of voltage for each DC a negative voltage between 0 and -1600 mV with a step less than 10 mV
Hardware architecture • OPI : a SUN workstation • 2 VMEs • one VME is dedicated for the 12 MM Ch and one Drift chamber • one VME is dedicated for 2 Drift chambers • 2 CAEN SY127 crates
Hardware architecture • CPUs : PPC MVME2431-1 • Boards for MM - ADAS ICV196 binary input output - home VME interface board - CAEN V288 • Boards for DC -ADAS ICV712 analog output for voltages of thresholds (-0.700 mV) - CAEN V288
HV CAEN system SY127 • Old system (1986) • CAENET (proprietary protocol) link between the VME and the CAEN crate • VME V288 • CAEN HS128 • Each module has 4 channels • Hardware protection • A634 for MM • 2KV 40 µA res 10 nA • 6 modules • A234 & A434 for DC • 2KV 200 mA res 100 nA • 9 modules • Firmware provided by CAEN • How does a HV channel work?
Software based on EPICS • Solaris 8 • EPICS R3.13.4 • medm, stripTool and alh for HV • Channel Archiver and xarr for HV • EPICS software for CAEN SY127 first developped by Dave Barker at JLAB in 1994 • some little modifications (negative polarity)
Home Made Software • Channel Access clients tasks for safety of chambers • SNL for MM thresholds • JAVA (JDK1.2) graphical interface for thresholds on-line configuration save & restore configurations • JAVA graphical interface for on-line errors • Graphical java tool for configuration of HV databases and displays
Future In 2005, a new magnet system ( built by Oxford Danfysik Lab) will be installed (superconducting solenoid, dipole, correction coil). EPICS will be used for fast acquisition ( see W7X at Collaboration Meeting KEK, May, 2000) and slow control.
SNL for Thresholds of Micromegas interrupt every 14 sec. ... ASCII file of configuration for 24 busses of 32 SFE16 chips of 4 registers of 12 bit 24 bit pattern 24 busses x 32 SFE16 JAVA graphical interface specific board SNL prog. ADAS ICV 196 archives ... VME configuration files