I. Vankov, NEC’2003, September ‘03, Varna HV PS System NEC’2003, September 03, VARNA CMS HCAL High Voltage Power Supply System Dimitrov L.(*), Kunov B.(*), Sergeev S.(**), Vankov I.(*) (*) INRNE, BAS, Sofia, (**) FNAL,USA/JINR,Dubna

I. Vankov, NEC’2003, September ‘03, Varna HV PS System Compact Muon Solenoid (CMS) - detector of The Large Hadron Collider (LHC) in CERN CMS Hadron Calorimeter (HCAL) consists of 50 mm brass plates with thin plastic scintillators between them Light collection is provided by wave length shifting fibers

I. Vankov, NEC’2003, September ‘03, Varna HV PS System HCAL Photodetectors - Proximity Focused Hybrid Photo Diodes (HPDs) Photocathodep-i-n diode U HV ~ 10 kV U BIAS ~ 100 V Operate in high magnetic field – to 3 Tesla In all HCAL about 500 HPDs 19 pixels

I. Vankov, NEC’2003, September ‘03, Varna HV PS System 500-channel PS system 226U Eurocrates 125 HV Modules HV Module – 4 HV and 4 BV channels SDLP unit – 5 LEDs and 4 trims – U HLIM, I HLIM, U BLIM, I BLIM Crate Power Supply: 48 V, U BLIM +10 V, 5 V +8 V, -8 V U BLIM (RS485) HOST PC 220 V CRATE POWER SUPPLY CRATE CONTROLLER MODULE 1 (4-CHANNEL HV AND BIAS VOLTAGE POWER SUPPLY) BV1 HV1 BV2 HV2 BV6 HV6 STATUS DISPLAY AND LIMITS PRESETTING MODULE 2 (4-CHANNEL HV AND BIAS VOLTAGE POWER SUPPLY) MODULE 6 (4-CHANNEL HV AND BIAS VOLTAGE POWER SUPPLY) BV1 HV1 BV2 HV2 BV6 HV6 HBV 1 HV1 BV2 HV2 BV6 HV6 Fig. 1. The HV system Crate block diagram. CRATELOKALBUSCRATELOKALBUS

I. Vankov, NEC’2003, September ‘03, Varna HV PS System Crate Controller: information exchange between the host computer and the crate via RS485 interface; controls the Power Supply modules using custom backplane interface; high and bias voltages setting – from the host computer; polling of all voltage and current output values as well as the voltage and current limit values; controls all crate supply voltages and gives alarm.

I. Vankov, NEC’2003, September ‘03, Varna HV PS System HV CHANNEL - DC-DC converter – kV BV CHANNEL – Linear stabilizer V CMP – overvoltage and overcurrent control DAC – voltage setting MPX+ADC – voltage and current measurement INTERLOCK – HV line integrity control

I. Vankov, NEC’2003, September ‘03, Varna HV PS System RES I BLIM I U BLIM I HLIM U HLIM CPU CONTROL LOGIC STATUS DISPLAY AND LIMITS PRESETTING ON U TRIP I TRIP CPS TEMP A[13..15] A[8..12] D[0..7] RxD TxD A[13..15] A[0..7] D[0..7] CNTRL[0..3] KILL KILL TxD RxD INTERFACE RS485 OUT RS485 IN Fig. 3. Crate Controller and Status display and Limits Presetting block diagram ST MD[0..3] CLK D-WR D-RD MEMORY CNTR[0..3] D[0..7] A[0..12] S[0] MD[0..3] CLK D-WR RES D-RD CPU - Intel single chip microcomputer (I 8031) RS 485 Interface with host computer CONTROL LOGIC – data exchange with modules MEMORY – stores all data – for Host KILL – high priority external command

I. Vankov, NEC’2003, September ‘03, Varna HV PS System Status Display LEDs · ON (green) – when it is dark all channels in the crate are off; when it is light the output voltage of all set channels are established; · U TRIP (red) – at least overvoltage in one channel is registered; · I TRIP (red) – at least overcurrent in one channel is registered; · CPS (red) – at least one of the crate power supply voltage values is out of range. · TEMP (red) – the inside temperature of the crate is above 50 0 C.

I. Vankov, NEC’2003, September ‘03, Varna HV PS System Status parameters displayed by the Host For each channel: on/off, ready, up/down, voltage fault, overvoltage, overcurrent For each module: on/off, overvoltage in any channel, over- curent in any channel, in any channel, activated interlock For each module: on/off, overvoltage, overcurrent, voltage fault, activated interlock in any module and others

I. Vankov, NEC’2003, September ‘03, Varna HV PS System Fig. 4. The Power Supply System control program package. PROGRAM PACKAGE: Client/Server architecture INTERFACE - Distributed Information Manager (DIM) PACKAGE PROGRAMS: Server programs Client programs Debugging tools

I. Vankov, NEC’2003, September ‘03, Varna HV PS System SERVER – up to 8 RS485 interfaces SERVER PROGRAMS: 1.Tools to set/retrieve the Power Supply system hardware configuration. 2.Tools to set and check serial ports. 3.Facilities to set DIM items names and alias names for a higher level monitoring system. 4.Publishing of the control information via DIM protocol. 5.Viewing of the published information for the debugging purposes.

I. Vankov, NEC’2003, September ‘03, Varna HV PS System CLIENT PROGRAMS: Control and monitor the Power Supply System (see fig. 5). Data recording tool – data archiving. Alarming program – acoustic signals ARCHIVE BROWSER DEBUGGING TOOLS: Hardware emulator – for checking RS485. DIM information browser.

I. Vankov, NEC’2003, September ‘03, Varna HV PS System Fig. 5. The main window of the Power Supply System monitoring tool. The server works under any Windows OS of Windows NT clone Clients works at different computers with Linux or Windows OS HCAL HV power supply system will be integrated in the HCAL Detector Control System (DCS) based on the PVSS II Supervisory Con- trol And Data Acquisition System toolkit.

I. Vankov, NEC’2003, September ‘03, Varna HV PS System Max operating voltage, V Max test voltage, V Voltage resolution step, V 4 0,05 Voltage ripple, mV p-p Ramp rate, V/s 0 – Long term stability, % 0,10,1 Voltage monitoring accuracy, % 1 1 Max output current, uA 4010 Current monitoring accuracy, % 1 1 Special Floating output Parameter High voltage Bias voltage

I. Vankov, NEC’2003, September ‘03, Varna HV PS System THANK YOU FOR THE ATTENTION