# Presentation: 417762

## MERIT Hg SystemFinal Design Review

**Hg Target System Controls**
**V.B. Graves**
**P.T. Spampinato**
**T.A. Gabriel**
**MERIT Collaboration Meeting**
**MIT Plasma Science & Fusion Center**
**Oct 5, 2005**

## Outline

**Operating environment**
**Requirements / constraints**
**Power requirements**
**Instrumentation**
**Control system scheme**
**Issues**

## CERN Tunnel Plan View

- A. Fabich, CERN

## MERIT Layout

## TT2A Photos

- Photos from A. Fabich, CERN

**Tunnel Width 400cm (158")**

**Width 1.3m (51")**

## Control System Requirements & Constraints

**No existing power available in tunnel**
**Control system mounted on hydraulic pump reservoir**
**Operator controls 60m away**
**Will require some level of communication with other control systems (solenoid, beam, diagnostics) and/or a supervisory control system**

## Operating Scenario

## Power Requirements

**Hydraulic pump – 380/460VAC, 50-60Hz, 60A**
**Proportional control valve – 24VDC**
**Heater foil – 120VAC**
**Hg vapor monitor – 120VAC**
**Instruments – 24VDC**

## Minimum Signal Requirements

**Trigger (time till pulse)**
**Ready signal from Hg system**
**Enable signal from supervisory control system**
**Also used as abort signal**

## Instrumentation & Sensors

| Controlled Components |  |  |  |
| --- | --- | --- | --- |
| Hydraulic pump | Proportional control valve* | Heater foil |  |
| Analog Sensor Inputs |  |  |  |
| Hg discharge pressure | Hg level | Hg sump thermocouple | Secondary containment thermocouple |
| Cylinder 1 position* | Cylinder 2 position | Hg vapor 1 | Hg vapor 2 |
| Hydraulic fluid high pressure | Hydraulic fluid low pressure | Beam window 1 pressure* | Beam window 2 pressure* |
| Digital Sensor Inputs |  |  |  |
| Hydraulic filter dirty switch | Hydraulic low level switch | Conductivity probe |  |

*** Critical for system operation or safety**

## Proportional Directional Control Valve

**Bosch Rexroth 4WREE**
**Operating pressure: up to 3000psi (210 bar)**
**Nominal flow: 8.45gpm (32 l/min)**
**Sensitivity: <= 0.05% (equates to 0.003 m/sec nozzle velocity)**
**Supply voltage: +****24VDC**
**Command signal: ±10VDC**

## Original Position Sensor

**Temposonics G-series linear position sensor**
**Measured variable: displacement**
**Measuring range: 2-100in**
**Repeatability: 0.001% full stroke**
**Output: voltage or current**
**Update time: <1ms**
**Supply voltage: +24VDC**
**Installed in hydraulic cylinder**
**Problems: on-board electronics, operates using magnetic field**

## Current Position Sensor

**Celesco CLWG linear potentiometer**
**Redundant sensor on cylinder #2**
**Aluminum body**
**Voltage divider output**
**Variable resistor, no on-board electronics**
**Repeatability < 0.01mm**
**Linearity 0.05%FS for 450mm range (0.225mm)**
**Position sensor critical to system control**
**Piston start/stop locations**
**Piston position/velocity ******** Hg flow rate ******** Jet velocity**
**Electrical noise may be problem**

## LabView-Based Control System

**Remote control over long distance limited choices**
**Analog I/O modules need to be close to equipment and power supplies**
**LabView controller on laptop computer was chosen**
**National Instruments recommends CompactPCI I/O modules**
**Communicates to laptop via EtherNet cable**
**Allows custom operator interface, data logging if required during development**
**Should allow straightforward integration with other control systems**
**Control system development to begin late October**

## Procurement

**National Instruments hardware & software procured by Princeton**
**LabView software already procured**
**Laptop computer provided by BNL**
**Most instruments specified in Hg delivery system procurement package**

## Conclusions

**Control system scheme chosen**
**System development to begin November 2005**
**Ready when syringe delivered**
**Most instruments provided with Hg delivery system**
**Integration with supervisory control system TBD**