Overview of Phobos Magnet Designed by Harald Enge Built by Danfysik Technical summary: –“Double dipole” design –15.5 cm air gap –Max. 2 Tesla field –378 kW power dissipation –High, uniform field inside gap –Small field outside gap Phobos Magnet is a conventional magnet

Position of Magnet System Components PS M 10 o’clock hall CT

Position of Magnet in Hall Outer Ring Wall

300mm 155mm 1950mm 843mm 4040mm Major Dimensions in Side View Floor 20 kN force 1170 kN

4040mm 1400mm 430mm Major Dimensions in Top View

Weights of the Components

Field in the Spectrometer

Stray Field Outer Wall Inner Wall

Jacks Magnet will be supported by 4 Jacks Jack Type Duff Norton M9015: –15 ton max load –12” Stroke 2 opposite jacks have a common drive shaft

Coil Distribution Box Berm penetration Coil Power Supply Electrical Path 150’ Cooled Buss

Power Supply Refurbished AGS power supply: –Acme Rectifier, type PS Input: 440 VAC; 682 A; 60 Hz Output taps: 75V, 88V, 105V and 125V –Phobos will use the 105V tap with 3600A current Internal Power Dissipation: 40 kW –air-cooled

Coils Coil consists of: –8 double pancakes with 6 turns per pancake –Square OFHC Cu-conductor 0.650” on a side and a 0.363” diameter cooling hole –Vacuum epoxy impregnation Pancakes electrically connected in series, hydraulicly in parallel. Power dissipated per coil is 85.4 kW 2 Coils are connected in series: –total 95V drop at 1800A

K K K K K K K Flow Double Pancake Klixon 8 parallel H 2 O circuits K Power In Power Out Connections at Coil

Coil Tests Danfysik will perform the following tests on the coils: Pre-impregnation tests: –Obstruction of coolant flow test –Test of turn-to-turn insulation –Test of leakage under pressure (up to 360 psig) Post-impregnation tests: –Test of coil-to-earth insulation at 2000 VDC (leakage current less than 20 microA). –Test of turn-to-turn insulation –Coil resistance –Water flow –Water temperature rise at 600A

Cooling Cooling Tower capacity of 0.5 MW A water flow at pressure differential 60 PSI at inlet temperature 45ºC permits operation at full power (378 kW) Flow rate of 11 liters/min and temp. rise of 14ºC per pancake –Total water flow through magnet: 352 liters/min 12.5 kW are dissipated in cooled buss Monitoring: –Temp. rise: Auto-reset Klixons set at 70ºC –Water flow: Paddle Flow meters

Pump Coil Cooling Tower Distribution Box Berm penetration Coil Cooling Water Path

Outer Wall Distribution Box Manifolding Side View

Outer Wall Manifolds Manifolding Top View

Mechanical Support Flux steel designed to deflect less than 1mm at full field strength –this design requirement is far from any safety margins Any one vertical support can withstand static plus magnetic load of yoke Magnet is stable: –17º tilt angle required –tilting requires 140 kN transverse force Magnet is “over-designed”

Interlocks PLC K K K... 4x8 Klixons Water mats Flow... 4 Flow meters Trips PS Shuts off Water Pump

Conclusion Standard normal coil magnet No unusual hazards Design by Enge Mechanical design is deflection limited Built by Danfysik Installed under BNL supervision We see no particular safety problems