Tower PMT Box


Twelve single-channel PMT’s, each in an

individual metal housing together with input optical

coupling and CW base “cell”.

CW base, with metal housing and RG-174

ouput cable.

Tower PMT Box


Besides the 12 PMT assemblies, the Tower PMT Box consists of the folloing components:

• clear 1.0 mm diameter Kurary plastic optical fiber (same as used in the barrel EMC)

• clear plastic tubing to sheath optical fiber bundles

• molded plastic optical connectors

• two CW base daisy-chain cables, each connecting six CW bases to a 10-pin connector on the

rear panelrear panel

• 12 RG174 coax cables: one end of each attached to base assembly, other end terminates in

LEMO connector

• 12 LEMO bulkhead connectors mounted on insulated panel on top of box

• Dallas Semiconductor DS1820 temperature sensor wired to connector on rear panel (Positronics

MGH series)

• heating resistor, wired to BNC connector on rear panel – this will only be used for testing at

IUCF, it will not be connected in installation on STAR

Tower PMT Box


Tower PMT High Voltage System


• Consists of Cockroft-Walton base assemblies (one per PMT) and controller modules. Each controller

supplies 4 branch cables.

• Cell (CW base assy) consists of a current-mode controlled charge pump, Cockroft-Walton voltage

multiplier, and a feedback control system; a PIC microcontroller manages the voltage setpoint and monitors

whether the system is in regulation.

• Commercial hardware (HVSys Co. – Dubna)

• Similar system is approved and in use at STAR in the TOFp system

• Up to 127 bases per branch (cable). For EEMC Tower readout, we will use 121 bases per branch.

• Branch cable is 10-conductor flat cable, two +5 V lines, one +160 V line, two I2C data lines, five grounds.• Branch cable is 10-conductor flat cable, two +5 V lines, one +160 V line, two I2C data lines, five grounds.

• Controller output on each branch +5 V output is hardware current limited by National Semiconductor

LM2672 switching regulator at 1.55 A (nom).

• Controller output on each branch +160 V output is hardware current limited at 300 mA by series pass

transistor.

• Each cell draws 2 – 5 mA from the +5 V lines and up to 550 µA from the +160 V line. Input current from

the +160 V line is hardware current limited (see following schematic).

• Total load on cable: up to 605 mA @ +5 V, up to 67 mA @ +160 V.

• Cell multiplier components potted in Dow “Sylgard 182” silicone elastomer.



AC Input

90-250 V

50-60 Hz

RS-232

control I/O

Controller

HVSys # SM512 6 branch cables (one per sector)

(connections shown on only one cable, others similar)

...

AC Input

90-250 V

50-60 Hz

RS-232

control I/O

Controller

HVSys # SM512

2 sub-branch cables per PMT box (10 boxes per sector),

each connects to six PMT / CW base assemblies

1 sub-branch cable per

sector in 2nd-level laser

splitter box, connects to

monitor PMT



• Branch cable is standard 28 AWG jacketed flat cable, Amphenol #159-2832-010

• Rated 1.3 A per conductor, 300V, UL CL-2

• Sub-branch cable (internal to Tower PMT Box) is standard 26 AWG flat cable (Belden 9L26010

or equivalent).

• Rated 1.5 A per conductor, UL 105°C, 300V, Style 2651, UL VW-1

• Connectors are standard flat cable connectors, 3M series 3473 & 4610

• Rated 1 A per conductor, 1000 VAC rms withstanding voltage, UL #E68080

• Unused connector positions on the branch cables will be covered with a rectangular plastic cap

to prevent any accidental contact with the connector pins.

HV

SY

S B

ranch

Cab

le


Tower PMT High Voltage SystemPartial schematic of cell, showing HV input,

current-regulated chopper switch, and feedback

Tower PMT Box Temperature Monitor


• 9U form-factor, comprised of standard 9U aluminum spacer module with small proto-board (Vector #8001,

UL 94V-0) attached.

• Installed in Tower FEE crates (a non-standard backplane).

• Draws power <100 mA @ +5 V from backplane, fused via ½ A, 125 V fuse.

• Standard 34-conductor twist-n-flat cable connects between Monitor Board and PMT Boxes. Cable is broken

out into eight 4-conductor sections, one to each PMT Box. Three cables per monitor board. Connector at

Monitor Board is 3M #3431, 1A, 1000 VAC rms withstanding, UL 94V-0. Connector at PMT Box is

Positronic MGH series, 3A, 250 VAC rms rated, UL recognized.

• DB-9 male connector (AMP #747840-4, 2A, 1000 VAC rms withstanding, UL 94V-0) on Monitor Board for • DB-9 male connector (AMP #747840-4, 2A, 1000 VAC rms withstanding, UL 94V-0) on Monitor Board for

RS-232 serial data output to EEMC Slow Controls VME crate in EEMC racks.

Data Collector System


• Standard STAR Wiener 6U VME crate

• 9 data collector input cards (custom board – IUCF)

• 2 data collector output cards (custom board – IUCF)

• commercial VME CPU module

• crate is mounted in EEMC west wall racks

First-level laser splitter box


Miscellaneous


• Second-level laser splitter box

• Contains one PMT and base assembly, equivalent in construction to 1/12 of a Tower PMT box.

• Laser System Timing and Intensity Monitor Electronics

• Various commercial NIM gate generator and logic modules located in EEMC west wall racks will

trigger the laser based on slow controls commands and timing from the TCD.

• Various commercial amplifier and ADC modules will receive the signals from the photodiodes in the

First-Level Laser Splitter Boxes and digitize the data for readout via slow controls.

••

g. visser iucf 8/30/02 star eemc electrical safety...

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