Ex-Situ NMR LDRD Progress report 1/27/03 1/27/03 1.Review of problem, status/plans - GianLuca 2.Magnetic and mechanical design- Paolo 3.Magnet configuration/fabrication - Scott

NMR Spectroscopy/Imaging NMR= Nuclear Magnetic Resonance MRI = Magnetic Resonance Imaging Interaction of nuclear spin (dipole moment) with static + RF fields Main nuclei which can be detected (i.e. net spin  0): 1 H, 2 H, 31 P, 23 Na, 14 N, 13 C, 19 F

Strategic LDRD Materials, Earth, Industrial Sensing, Counterterrorism EETD, ESD Molecular target recognition, drug Discovery PBD In vivo diagnostic imaging, therapy appraisal LSD NMR/MRI Methodology & Instrumentation MSD Scanning Superconducting Ex-situ magnets AFRD

Advanced NMR Techniques

Ex-situ NMR Pines et al., Science 293, pp. 82, July 2001

Ex-situ Supercond. Magnet LDRD Goal: design, fabricate and test a prototype magnet with: - higher field (4x or 2000 Gauss) - better field quality (10 -3 in 3 mm diam) than was achieved using permanent magnets (Ref: Fukuhara et al., “Novel NMR apparatus for Investigating an external sample”, J. Magn. Reson. 97, , 1992) We did not promise NMR integrated system, but may consider a proof-of-principle experiment. Try to develop on SM design/fabrication concepts.

Original design concept x y z Racetrack coils (SM). SSC outer, 32 strands. Six blocks w/opposing currents. Support structure (bolted, skins, bladders) Low (15 MPa) lateral stress on coil NMR analysis volume

Field strength/quality Permanent magnet device (500 Gauss) Superconducting version (2000 Gauss) Field quality: ~10 -2 in 1 cm

Original Work Plan Design: - Analyze/compare different design concepts - Field optimization (strength, homogeneity, tunability) - Analysis of NbTi (baseline) vs. Nb3Sn version - Support structure: bladders (baseline), bolted, skins - Effect of magnetic interactions along x-axis Fabrication: - Use SM design concept to the extent possible - Winding issues (small pole radius) - Splice design Test: - Training, ramp rate, Hall probe field measurement - Rotating probe measurements in warm bore ? - NMR test in warm bore ?

Original Schedule OctNovDecJanFebMarAprMayJun Conductor & parts Fabrication Test FY04 LDRD DEADLINE Test prep. Analysis Design PAC 2003 PORTLAND DOE REVIEW

Coil configurations (1) HD (original) RD (alternative)

Coil configurations (2) HD: + Fewer coils + More efficient magnetically - Fewer degrees of freedom - Tight bending radius - Thin structure for prestress - Vertical forces - Requires new coils RD: - More coils - Less efficient magnetically + More degrees of freedom + Large bending radius + Better aspect ratio + More stable against y-force + Can use Nb3Sn SM coils

“SM”configuration Analysis volume Six SM coils in series

LDRD Status - General considerations: Work started 2.5 months late, due to other commitments LDRD goal: fabricate & test a prototype with specified parameters New coil design always requires big effort (RD, SM, HD) - SM configuration advantages: 3 coils available (SC-01, SC-02, SC-04) 2 more baselines already in SM plan Parts for 2+4 additional coils are available - SM configuration issues: Loss of efficiency due to insufficient island thickness (compesated by use of Nb3Sn) 3D field optimization (insufficient ratio of coil length to saddle point distance. Original proposal: 20 mm, presently working with 45 mm)

Proposed plan 1. Proceed with the first prototype: Start coil fabrication (2 SM + 2 NMR) Define support structure detail, start procurement Coil position, iron geometry optimization 2. In parallel: Explore performance limits for a fully optimized magnet Goal for today’s meeting is to review the design and get feedback on the proposed plan