High B/T Facility: 2014 UPDATE Neil Sullivan 2014 Users Committee Meeting Tallahassee, FL October 10-11, 2014

NHMFL HIGH B/T FACILITY Mission Enable user research in High Magnetic Fields at Ultra-Low Temperatures in an Ultra-Quiet Environment. Nuclear Demagnetization Refrigerators: (1)PrNi 5 : T MIN ~ 0.3 mK (16.5 T) (2)Cu: T MIN ~ 0.1 mK (8 T) Experiments are long (6-8 months) staff intensive, and costly ( liters liq. He/experiment) Dilution Refrigerator (Annex Bldg) 40 mK, 10 T, Fast turnaround User Needs: Access to higher B: Long-term plan, add HTS 32 T magnet Short term: EAC Recommendation: Add 18T/3mK Dil. Fridge Combo BOTH need to be located in new space (New Physics Bldg?)

High B/T Physics AMRIS 700 m Remote Site (New Physics Building) High Bay Area Need additional staff and instrumentation High B/T site New Physics Building

Research Areas High B/T Facility Growth: Typical experiment: 1 PI, 2.5 Co-PIs 1 local collaborator, 1 sample maker 1 sample characterization 0.5 postdoctoral fellow, 0.5 graduate student. Fabrication of sample mount Lasts 6-18 months (varies widely) Uses liters liq. He Origin PIs helium costs funding No. Users publications Opened Bay 2

1."The experiment … is my first time to collaborate with NHFML researchers and get machine time to perform AC susceptibility measurements at ultra-low temperatures. In this program, everything was going on well and we have not met any problems. We hope to be able to have more chance to perform nice measurements in NHFML facilities.“ 2.“Prof Yasu Takano was very helpful. He realized that the capacitance effect induced in the long cables contributed some small background when the data was being taken.” 3.“Every aspect of this experiment went extremely well. At the start, we knew that we were further characterizing a set of detection coils that had been used previously and that might become available for other Users. Indeed, we were successful in addressing this technical issue and in studying the underlying magnetic interactions of some novel materials supplied by a group from China. This group had not previously used the NHMFL facilities.“ 1.Is there accommodation support similar to that available in Tallahassee Reitz Union has parking as well as hotel accommodation User Feedback Comments Informal Comments

High B/T Facility 0.05 mK + 8T vector magnet Weaknesses Long wait time in queue for magnet time after proposal acceptance --- cannot respond rapidly for users competing in “hot” areas Limited staff -- two supported by NHMFL, two by UF --- insufficient to operate robust user facility Threats Rapid growth of High B/T at Laboratory for Extreme Conditions (China) (considerable resources) Also Inst. Solid State Physics, (Vienna Univ. of Technology) Aging infrastructure (Tallahassee has helped in emergencies)

NHMFL High B/T Facility FUTURE DIRECTIONS I.Higher Magnetic Fields Extend parameter space, Plan for HTS 32 T ( ) Short term: EAC Recommendation Dil. Fridge/18 T combo. High pressure at very low T (James Hamlin) (QPT, magnetization studies etc.) ….. would be unique II. Development LT Instrumentation Exploit LT environment, High sensitivity measurements low temperature electronics, high sens. NMR, NQR, SQUIDs (frustrated magnets, heavy fermions ….) High frequency NMR re-entrant cavity Diffusion liquid 3 He: Sub-mK susceptibility studies Qu. Phase Transitions