HIGH VOLTAGE POWER SUPPLY SYSTEM FOR CMS FORWARD SUBDETECTOR
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Transcript of HIGH VOLTAGE POWER SUPPLY SYSTEM FOR CMS FORWARD SUBDETECTOR
HIGH VOLTAGE POWER SUPPLY SYSTEM FOR CMS FORWARD SUBDETECTOR
Lubomir Dimitrov, Ivan VankovNuclear Electronics Laboratory, Institute for Nuclear Research
and Nuclear Energy, BAS
I. Vankov ET 2004, Sozopol, Sept. 2004
HV PSS for HF
I. Vankov ET 2004, Sozopol, Sept. 2004
HV PSS for HFLHC TUNNEL
I. Vankov ET 2004, Sozopol, Sept. 2004
Compact Muon Solenoid (CMS)
HV PSS for HF
HE HB
HF2HF1
I. Vankov ET 2004, Sozopol, Sept. 2004
HV PSS for HF
I. Vankov ET 2004, Sozopol, Sept. 2004
VERY FORWARD HADRON CALORIMETER (HF)
Copper Block
Cherenkov Detectors –
Embedded Quartz Fibers
1728 Photomultiplyers (PMTs)
Type Hamamatsu R7525
(8 stages: 7 dynodes + anode)
PROBLEMS CLASSIC SOLUTION: INDIVIDUAL RESISTOR DIVIDERS
– GENERATE ALL PMT 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
HV PSS for HF
I. Vankov ET 2004, Sozopol, Sept. 2004
I. Vankov ET 2004, Sozopol, Sept. 2004
HV PSS for HF
SYSTEM CONSTRUCTION
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)
AT EACH PCB – 8 PMTs
(with similar parameters)
HV PSS for HF
I. Vankov ET 2004, Sozopol, Sept. 2004
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
HV PSS for HF
I. Vankov ET 2004, Sozopol, Sept. 2004
PRINTED BOARD CIRCUIT 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
HV PSS for HF
I. Vankov ET 2004, Sozopol, Sept. 2004
ONE 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 CHANNEL SUPPLIES 9 PCBs
3 GROUPS OF 72 PMTs WITH SIMILAR PARAMETERS
1x12 WIRES 150 m HV CABLE 2x2 WIRES 15 m CABLES
HV PSS for HF
I. Vankov ET 2004, Sozopol, Sept. 2004
HV CHANNELS PARAMETERSPARAMETER CHANNELS
1, 4, 7CHANNELS
2, 5, 8CHANNELS
3, 6, 9
Max. output voltage, V 2000 800 400
Voltage resolution step, V
1 1 1
Output ripple, mVP-P 300 300 300
Floating output Yes Yes yes
Max output current, mA
0,5 0,5 0,5
Long tem stability, % <0,1 <0,1 <0,1
HV PSS for HF
I. Vankov ET 2004, Sozopol, Sept. 2004
CONCLUSIONS
1. HV SYSTEM NEW SOLUTION:
• PMTs united in groups with similar parameters;
• Only first 6 dynodes supplied by resistor divider, D7 and D8 – from individual HV channels;
• 9 PCBs (72 PMTs) connected to each HV channel.
2. ACHIEVED RESULTS:
• Drastically decreasing of numbers of the long HV cables – 8 instead of 144;
• Decreasing of the power losses and heating
• Drastically decreasing of the expenses