Hall B CryogenicsCLAS and CLAS12

David KashyHall B Lead Engineer

May 26, 2010

CLAS• Cryogenic Components

– Transfer line from ESR– 6 coil torroidal field magnet with service module –built by Oxford

Instruments operating since 1995– 500 liter liquid helium dewar – standard product with 2 liquid

withdrawal bayonets and cold gas return– Liquid helium cooled cryo-target - capable of liquefying hydrogen,

deuterium, He4 and He3– Frost Target and 5 Tesla Polarizing Magnet– 5T Polarized Target – cooled with LHe– 4.7T Solenoid – cooled with LHe – HDIce – In development also cooled with LHe

CLAS Cryogenic Hardware

CLAS OXFORD Torus

Frost Polarizing Solenoid

Cryofab 500 l Buffer Dewar

4.7 T DVCS Solenoid Photon Target Cell 40 x 4cm

Microwave Polarized Target

Electron Target Cell 2.5 x 1cm

30mK FROST Target

Scheduled Experiments 2010-2012

• Frost: Torus, Buffer Dewar, Frost Target and Polarizing Magnet

• HDIce/HD DVCS: Torus, Buffer Dewar and In-Beam-Cryostat

• Primex: No cryogenics, but keep Torus cold

• Two Photon Exchange: Torus, Buffer Dewar and Standard Cryotarget

CLAS Loads

• Torus: 110 Watts and 0.6 g/s lead cooling• Transfer Lines and Buffer Dewar: 30 Watts• Targets and Solenoids – All are of same order

of magnitude ≤ 1g/s (liquefaction loads)• LN2 – 7 g/s including TL

CLAS 12• Cryogenic Components

– Transfer line from ESR– 500 liter liquid helium dewar – standard product with 2 liquid

withdrawal bayonets and cold gas return– Liquid helium cooled cryo-target - capable of liquefying hydrogen,

deuterium, He4 and He3– New 6 coil torroidal field magnet with service module – New 5 Tesla Solenoid Magnet– New Distribution Can for both magnets and connection of Buffer

Dewar– New Polarized Target– HDIce – In development also cooled with LHe

CLAS 12 New hardware

Torus – WANG NMR

Solenoid – WANG NMR

Distribution Box

CLAS12 Loads

• Torus: 100 Watts and 0.6 g/s lead cooling (per specification note: Vendor claims less)

• Solenoid 70 Watts and 0.6 g/s lead cooling (per specification note: Vendor claims less)

• Transfer Lines, Distribution Box and Buffer Dewar: 60 Watts

• Targets– All are of same order of magnitude ≤ 1g/s (liquefaction loads)

• LN2 – ~10 g/s including TL

CLAS12 Load Summary

• Refrigeration load 230W• Liquefaction load 2.2 g/s• LN2 10g/s• LHe Inventory 1150 liter• LN2 Inventory 200 liter

Start up date April 2013Duration 10+ years

Questions?