CEA-SACLAY/DAPNIA1

Françoise Gougnaud

Slow control for Compass Saclay chambers

CEA-SACLAY/DAPNIA2

Micromegas & drift

chambers

CEA-SACLAY/DAPNIA3

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)

CEA-SACLAY/DAPNIA4

• 2002: 12 MICROMEGAS (MICRO MEsh GASeous) chambers and 3 Drift chambers installed

CEA-SACLAY/DAPNIA5

Slow control for High 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

CEA-SACLAY/DAPNIA6

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

CEA-SACLAY/DAPNIA7

• 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

Hardware architecture

CEA-SACLAY/DAPNIA8

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?

CEA-SACLAY/DAPNIA9

• 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)

Software based on EPICS

CEA-SACLAY/DAPNIA10

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

CEA-SACLAY/DAPNIA11

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.

CEA-SACLAY/DAPNIA12

CEA-SACLAY/DAPNIA13

One bus Micromegas

CEA-SACLAY/DAPNIA14

Displays for HV

CEA-SACLAY/DAPNIA15

Alh

CEA-SACLAY/DAPNIA16

JAVAgraphicalinterface

SNLprog.

archives

ASCII file of configurationfor 24 bussesof 32 SFE16chips of 4 registersof 12 bit A

DA

S I

CV

196

spec

i fi c

boar

d

interruptevery 14 sec.

VME

...

24 b

usse

s x

32

SFE

16

...

configurationfiles

SNL for Thresholds of Micromegas

24 bit pattern

CEA-SACLAY/DAPNIA17

Display of the 24 busses for MM

CEA-SACLAY/DAPNIA18

Thresholds configuration on-line

CEA-SACLAY/DAPNIA19

Micromegas chamber

CEA-SACLAY/DAPNIA20

Drift chamber

CEA-SACLAY/DAPNIA21

Configuration tool in java