crystal ball meeting 7th -9th april, dubrovnik

Mauricio Martínez Fabregate Dubrovnik, April 8th 2008

Crystal Ball Meeting 7th -9th April, Dubrovnik

Status of theMainz Frozen Spin Target

Institut für KernphysikJohannes Gutenberg-Universität Mainz


Status of the Mainz Frozen Spin Target

• Frozen Spin Target• Polarization method• Microwave system• Target material• Polarizing magnet• Cryostat temperatures• Cryostat internal holding coil• Conclusions & Outlook


Cryostat

The Mainz Frozen Spin Target

Target

MicrowaveSystem

Magnet

Pumping SystemNMRL C

HHHH

HOCCCCH

HHHH

N

O

CH3

CH3CH3

CH3

Butanol+

Doping

ControlSystem


Rail system needed

Cryostat

Polarizingmagnet

Crystal Ball

Polarization method

1. External magnet 2.5 T2. Polarize with microwaves3. Internal holding coil 0.7 T4. Remove external magnet5. Move CB detector in. 6. Data taking.7. Repolarization

Polarizingmagnet

MicrowavesMicrowaves


Target Polarization GDH

June 2003 July 2003


The Mainz Frozen Spin Target

PolarizingMagnetMicrowaves

Targetmaterial


Microwave setup

Source

Power Sensors

Frequency sensor

Power meter

Frequency counter

Targetmaterial

Computer control

Power supply


Target material


Polarizingmagnet

He4(liq)

Mauricio Martínez Fabregate Dubrovnik, April 8th 2008 Start

Mauricio Martínez Fabregate Dubrovnik, April 8th 2008 Stop


Mainz-Dubna Cryostat

•Separator (3K) and Evaporator (1.2K) precooling stages. Evaporator cryostatHe4 line.

•Target insert along the beam axis•Fits in the geometry of the Crystal Ball detector: Horizontal•Superconducting holding coil integrated

•Temperatures of

30 mK He3-He4 mixture. Dilution Cryostat

He3 line



Temp Mixing Chamber

0

50

100

150

200

250

300

350

400

450

500

12/12/20070:00

12/12/20074:48

12/12/20079:36

12/12/200714:24

12/12/200719:12

13/12/20070:00

Time

Tem

p (

mK

)

30 mK !


· Current leads (46A): Copper (6mm2) T=300K 70 KHTc Supracond. T= 70K 4 K

NbTi 200m T= 4K 1.5K

Internal

Holding coil1.3Kelvin

1 Tesla at 46A

L=136mm, d=48mm, 4 layers

Support Copper-tube d=0.3mm


Coil production in theMechanics workshop


Conclusions & Outlook• Microwave system ready• Target material in Mainz• Polarizing magnet ready• Cryostat temperature 30 mK• Cryostat internal holding coil working

• Rail system for CB (Next months)• Polarize and measure target of material (Spring)• Move target into the A2 hall (Summer)• First polarized data (Winter)

• Diplom-student with transverse polarized coil


Target GroupAndreas Thomas

Mauricio Martínez Garik Palagasvilik Oleksandr Kostivov

Sasha NeganovNicolai Borinov

Yuri Usov+

Rudolf KondradievMilorad KorolijaHenry OrtegaPatricia Aguar

+Bonn & Bochum

+Joachim, Mohamed,

Vicenta, Noelia, Dave,Steven, Chris…

crystal ball meeting 7th -9th april, dubrovnik

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