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Re 4 + S=3/2. Status and Highlights: EMR. f = 934 GHz. Commercial instruments. Pulsed. Program growth in 2009 - 2010:. Hiring of a new Scholar Scientist in biochemistry* New push into biochemistry (future acquisition of HiPER)* Many new users, and increased numbers of users*
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Re4+ S=3/2 Status and Highlights: EMR f = 934 GHz Commercial instruments • Pulsed
Program growth in 2009 - 2010: • Hiring of a new Scholar Scientist in biochemistry* • New push into biochemistry (future acquisition of HiPER)* • Many new users, and increased numbers of users* • World’s highest frequency pulsed EPR spectrometer (336 GHz) • Expanded continuous frequency coverage to 1 THz (35 T for g=2)* • High resolution EPR increased to 700 GHz in 25 T Keck magnet* • Addition of Mössbauer spectroscopy to user instrumentation • Development of EPR under pressure (separate NSF CHE funding) • ~10% of NHMFL publications (~40 per year) • Quality publications (past 2 years): JACS 11; PRL 9; Nature Mat. 1; • Nature Phys. 1; PNAS 1; PRB 9; Inorg. Chem. 18; Dalton 5; Biochem. 1. • *Specifically discussed in the previous renewal proposal Status and Highlights: EMR Milestones:
EMR growth: High-resolution HFEPR Tryptophan (Trp) radical in azurin, an electron transfer protein S. Stoll, D. Britt UC Davis • g tensor characteristic of microenvironment . • Compare to electronic structure calculation. • Crucial for systems with small g anisotropy (tryptophans, tetra-pyrroles, e.g., chloro-phylls, and organic photovoltaic materials)
Magnetic atoms with strong spin-orbit coupling (5d, 4f, even 5f) • 1D single-chain magnet • Slow quantum dynamics JACS2010, 132, 3980 EMR growth: Molecular Nanomagnetism Re4+: [Xe] 4f14 5d3 S = 3/2 T = 1.3 K
Existing sources + new magnets (SCH/split-gap) • Will require improved 1+ THz probes • Future sources (BigLight) & highest fields (60 T) • 1Short-term; 2longer-term Future growth: Ultra-high fields/frequencies Low-loss quasi-optics & corrugated waveguide All-optical HF-EPR in split-gap magnet(s) Series connected hybrid Split- Gap magnet
Significant growth in program has so-far occurred without a corresponding growth in the number of postdocs and students • This is taking its toll on the user support staff • More and more time devoted to user support • Less time on proposal and instrument development • Increased staffing support needed EMR growth: personnel/staffing