PHOTOMULTIPLIER HIGH VOLTAGE POWER SUPPLY SYSTEM FOR THE

CMS FORWARD HADRON CALORIMETER

Lubomir Dimitrov, Ivan Vankov

Nuclear Electronics Laboratory, Institute for Nuclear Research and Nuclear Energy, BAS

Serguei Sergeev

Fermi National Laboratory, USA/Joint Institute for Nuclear Research, Dubna, Russia

I. Vankov NEC’2005, Varna, Sept. 2005

PMT HV PSS for HF

I. Vankov NEC’2005, Varna, Sept. 2005

1. INTRODUCTION.

2. POWER SUPPLY SYSTEM

3. HV POWER SUPPLY MODULE

4. CRATE CONTROLLER MODULE AND MONITOR AND CONTROL UNIT

5. POWER SUPPLY SYSTEM SOFTWARE

6. BASIC TECHNICAL PARAMETERS

7. CONCLUSIONS

Compact Muon Solenoid (CMS)

PMT HV PSS for HF - INTRODUCTION 1

HE HB

HF2HF1

I. Vankov NEC’2005, Varna, Sept. 2005

FORWARD HADRON CALORIMETER (HF)

Copper Block

Cerenkov Detectors –

Embedded Quartz Fibers

1728 Photomultiplyers (PMTs)

Type Hamamatsu R7525

(8 dynodes)

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PMT HV PSS for HF - INTRODUCTION 2

PROBLEMS CLASSIC SOLUTION: INDIVIDUAL RESISTOR

DIVIDERS – GENERATE ALL PMT DYNODE VOLTAGES, BUT:

1. NEED 1728 HIGH VOLTAGE CHANNELS and 1728 165 m long HV CABLES - VERY EXPENSIVE

2. LARGE SPACE FOR THE 1728 DIVIDERS

3. GREAT POWER LOSSES IN THE DIVIDERS – PRODUCE MUCH HEAT

PMT HV PSS for HF - INTRODUCTION 3

I. Vankov NEC’2005, Varna, Sept. 2005

PMT HV PSS for HF - INTRODUCTION 4

SPECIFIC SYSTEM STRUCTURE

proposed by Dr. David Winn from Fairfield University 72 READ OUT BOXES (ROBOXES) –

36 for HF1 and 36 for HF2

36 roboxes – divided to 4 group of 9 corresponding to the four HF quadrants

IN EACH ROBOX – 3 PRINTED CIRCUIT BOARDS (PCBs) WITH 8 PMTs

HAVING VERY SIMILAR GAIN/VOLTAGE

I. Vankov NEC’2005, Varna, Sept. 2005

PMT HV PSS for HF - INTRODUCTION 5

D1

D2

K

D3

D4

D5

D6

D7

D8

A

S

ID50 μA

D1

D2

K

D3

D4

D5

D6

D7

D8

A

S

A

B

C

D

E

F

A

B

C

D

F

E

D1

D2

K

D3

D4

D5

D6

D7

D8

A

S

A

B

C

D

F

E

PMT

No1

PMT

No2

PMT

No8

LG

UK

UD7

UD8

PRINTED CIRCUIT BOARD DIAGRAM

I. Vankov NEC’2005, Varna, Sept. 2005

PMT HV PSS for HF - INTRODUCTION 6

I. Vankov NEC’2005, Varna, Sept. 2005

PRINTED CIRCUIT BOARD WITH 8 PMTs

ONE RESISTOR DIVIDER FOR THE FIRST 6 DYNODES

WITH TOTAL RESISTANCE ABOUT 20 Mohms –

MAX. CURRENT < 50 uA

THREE SUPPLY VOLTAGES:

UK = 2000 V; UD7 = 800 V; UD8 = 400 V

RESULTS: STABLE VOLTAGE TO D7 AND D8

VERY LOW POWER LOSSES

PMT HV PSS for HF - INTRODUCTION 6ONE QUADRANT HV SYSTEM STRUCTURE

PS3

PS2

PS1

ROBOX No 13 PCs x 8

PMTs

Cable No 1

Cable No 2

Cable No 9

9 HV cablesL15 m

1 HV cableL150 m

ROBOX No 2

ROBOX No 9

HV MODULE No 1

UUD7,1

LG

UD8,1

UK,1

UUD7,2

LG

UD8,2

UK,2

UD7,2

LG

UD8,2

UK,2

UD7,1

LG

UD8,1

UK,1

UD7,3

LG

UD8,3

UK,3

UUD7,3

LG

UD8,3

UK,3

9 HV CHANNELS = 1 MODULE

1 CLUSTER SUPPLIES 9 PCBs

3 GROUPS OF 72 PMTs WITH SIMILAR PARAMETERS

1x9 HV WIRES 165 m CABLE 9x9 HV WIRES 15 m CABLES

I. Vankov NEC’2005, Varna, Sept. 2005

PMT HV PSS for HF – CRATE DIAGRAM

RS485

HOST PC

220 V CRATE POWER SUPPLY

CRATE CONTROLLER

HV POWER

SUPPLY MODULE 1

MONITOR

AND CONTROL UNIT

HV POWER SUPPLY

MODULE 2

HV POWER SUPPLY

MODULE 4

CRA T E

L O C AL

B U S

A1 A2 A3 B1 B2

C1 B3

C2 C3

A1 A2 A3 B1 B2

C1 B3

C2 C3

A1 A2 A3 B1 B2

C1 B3

C2 C3

4 HV POWER SUPPLY MODULES

3 HV CLUSTERS A, B, C

CRATE CONTROLLER MODULE

RS 485 – CRATE LOCAL BUS

MONITOR AND CONTROL UNIT

7 LEDs – SYSTEM STATUS

4 LIMITS – Uklim, Ilim1, Ilim2, Ilim3

CRATE POWER SUPPLY

+5 V, +8 V, -8 V, +40 V

I. Vankov NEC’2005, Varna, Sept. 2005

PMT HV PSS for HF – CRATE PHOTO

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PMT HV PSS for HF – HV MODULE 1A1, B1, C1 – 0 to 2000 V

A2, B2, C2 – 0 to 800 V

A3, B3, C3 – 0 to 400 V

FLOATING OUTPUTS

ONE CHANNEL:

DAC – HV SET VALUE

DC-DC CONVERTER

2 CMPs – U and I

LOCAL CONTROL

MUX+12 bits ADC

INTERLOCK

LED CONTROL

I. Vankov NEC’2005, Varna, Sept. 2005

PMT HV PSS for HF – HV MODULE 2

I. Vankov NEC’2005, Varna, Sept. 2005

RS485 INTERFACE WITH HOST COMPUTER

CRATE LOCAL BUS + CUSTOM PROTOCOL

7 LEDS – STATUS OF THE SYSTEM

4 POTENTIOMETERS – U and I LIMIT VALUES

A NEW FIRMWARE HAS BEEN DEVELOPED WHICH

IS NOW CAPABLE TO CONTROL BOTH HCAL

AND HF PS SYSTEM RECOGNIZING THE

DIFFERENT TYPE OF MODULES BY THEIR

UNIQUE ID NUMBER.

PMT HV PSS for HF – CONTROL & DISPLAY

Fig. 8. Crate controller module with the monitor and control unit block diagram.

CPU CONTROL LOGIC

MONITOR AND

CONTROL UNIT

POWER ON

CHANNEL ON

VOLTAGE PROT

CURRENT PROT

OVER HEAT

INTERLOCK

POWER FAILURE

A[13..15]

A[8..12]

D[0..7]

RxD

TxD

A[13.. 15 ]

A[0..7]

D[0..7]

CNTRL[0..3]

KILL

TxD

RxD

INTERFACE

RS485 OUT

RS485 IN

S T

MD[0..3]

CLK

D -WR

D -RD

RES

UKlim

I

I

I

MEMORY

CNTR[0..3]

D[0..7]

A[0..12]

S[0]

MD[0..3]

CLK

D -WR

RES

D-RD

KILL

lim1

lim2

lim3

I. Vankov NEC’2005, Varna, Sept. 2005

PMT HV PSS for HF – SOFTWARE

VERY SIMILAR TO THE HPD POWER SUPPLY SYSTEM

MAIN MONITOR WINDOW

NINE CHANNELS STATUS LIMIT VALUES

VOLTAGE UP/DOWN RATES CRATE PS VOLTAGES

MODULE STATUS

I. Vankov NEC’2005, Varna, Sept. 2005

HV PSS for HF - PARAMETERS

I. Vankov NEC’2005, Varna, Sept. 2005

PARAMETERCHANNELSA1,B1,C1

CHANNELSA2,B2,C2

CHANNELSA3,B3,C3

Max. operating voltage, VVoltage adjustment step, VRamp rate, V/sVoltage ripple, mVp-p Voltage monitoring inaccuracy, % Long term instability, % Max. output current, mACurrent monitoring inaccuracy, % Special

20000.5

5 – 500100

< 0,1< 0,10,8< 1

Floating output

8000.2

2 – 20040

< 0,1< 0,10,8< 1

Floating output

4000.1

1 – 100 20

< 0,1< 0,10,8< 1

FloatingOutput

HV PSS for HFCONCLUSIONS

HV SYSTEM FOR HF PHOTODETECTORS OF 2 CRATES WITH 4 HV MODULES

DESIGNED AND PRODUCED

LONG TERM TEST CONFIRMED THE BASIC SYSTEM PARAMETERS AND ITS

RELIABILITY

I. Vankov NEC’2005, Varna, Sept. 2005