1 / 7

Targets for SoLID Experiments

Targets for SoLID Experiments. Jian-ping Chen SoLID Collaboration Meeting Feb 3-4, 2012. Overview of SoLID Target Systems. Cryotarget system for PVDIS

verdad
Download Presentation

Targets for SoLID Experiments

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Targets for SoLID Experiments Jian-ping Chen SoLID Collaboration Meeting Feb 3-4, 2012

  2. Overview of SoLID Target Systems • Cryotarget system for PVDIS • 1kW Cryotarget (LH2/LD2) system with capability of solid targets in a large acceptance strong magnetic field • G0 type as starting design. • Target polarization due to field • Polarized 3He target system for SoLID-SIDIS(n/3He) • Standard type with achieved performance • SoLID field effect: end cap design • Improvements • Polarized NH3 target system for SoLID-SIDIS(p) (conditional approved) • Transverse Polarization with opening up to +-25 degrees • Design underway • Effects due to strong field

  3. Cryotarget: General Requirements/Considerations • 50 uA on 40 cm LD2/LH2, ~800 W beam power, ~ 1 KW total power • Solid targets: multi-foil 12C (optics), Al (dummy), BeO (viewer), … • Large acceptance, 2p azimuthal opening, 20-35 degrees q angle • Density fluctuations -- moderate requirement • Polarization effect to be < 10-6

  4. G0 Style Target for SoLID

  5. Target polarization in strong magnetic field • Small target polarization will introduce large false asymmetry due to • double spin asymmetry • Ortho-para configurations in LH2 • 2 protons form I=1 (ortho) and I=0 (para) state • at room T, ~75% ortho, 25% para (in equilibrium) • at T=20K, ~0.2% ortho, ~99.8% para (in equilibrium) • only ortho state can not be polarized • Chris Keith: P(ortho) ~ 50 ppm @ 20K, 1T  P(LH2) ~ 0.1 ppm • LD2: at 20K, 1T, P ~ 8 ppm (Chris Keith) • When hydrogen is cooled down it will have ortho to para conversion, but the spontaneous conversion process is slow • A catalyst like ferric oxide, active carbon, … can speed it up significantly • It was used at the early stage in Hall A cryotarget for LH2 target

  6. Polarized 3He Target • Existing performance: • luminosity: 1036 • polarization: 60% polarization • spin reverse: 10-20 minutes • Field gradients from Solenoid: • need careful design on endcap to minimize fringe field • existing design would require 30-50 mg/cm • new convention flow target would significantly reduce requirement • new upgrade would increase luminosity by a factor of 4-10, can SoLID take advantage of it? • Collimator design

  7. Polarized Proton (NH3) Target • Main issue: large opening angle for transverse polarization • +-25 degrees (cone) • keep to 5T if possible • no requirements on longitudinal • Don Crabb Contacting both Oxford and Scientific Magnetics • both can have a design satisfying these spec’s • Scientific Magnetics, initial quick look, it can be done, cost $600K • Oxford, modify from the Hall B design, give a quote to do detailed design • Forces between target magnets and Solenoid: need Tosca calculation

More Related