High B/T Facility: Update

1. High B/T Facility: Update • Neil Sullivan • 2014 Users Committee Meeting • Tallahassee, FL • October 10-11, 2014

2. 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: • PrNi5: TMIN ~ 0.3 mK (16.5 T) • Cu: TMIN ~ 0.1 mK(8 T) • Experiments are long (6-18 months) • staff intensive, and costly (4000-6000 liters liq. He/experiment) Dilution Refrigerator (Annex Bldg) 10 T, Fast turnaround, TSample~ 30-40 mK • User Needs: • Reduce queue (current 6-9 months): • (i) 2012 Propose open Bay 1 (need staff, equipment) • (ii) EAC Recommendation 2013 (short term): Add 18T/3mK Dil. Fridge Combo • (iii) Long-term plan: Access to higher B:add HTS 32 T magnet • BOTH (ii) & (iii) need to be located in new space (New Physics Building)

3. HIGH B/T OPERATIONS MICROKELVIN LAB. & WILLIAMSON ANNEX < 2007: Bay 3 only 2007 --- added Bay 2 (part-time) > 2015 plan to add HTS magnet

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

5. High B/T Facility Growth: 2006-14 Helium costs ($1k) No. Users Funding ($10k) Publications 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 4000-6000 liters liq. He Opened Bay 2 + Annex Research Areas Origin PIs

6. User Feedback Comments 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.“ “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.” “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.“ Is there accommodation support similar to that available in Tallahassee Reitz Union has parking as well as hotel accommodation Informal Comments Informal Comments

7. High B/T Facility • 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 • Competition • 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) 0.05 mK + 8T vector magnet

8. NHMFL High B/T Facility FUTURE DIRECTIONS High frequency NMR re-entrant cavity Diffusion liquid 3He: • Reduce Queue: Open Bay 1 (need staff, instrumentation) • Higher Magnetic Fields • Extend parameter space, Plan for HTS 32 T (2016-18) • Short term: EAC Recommendation Dil. Fridge/18 T combo. • High pressure at very low T (James Hamlin) • (QPT, magnetization studies etc.) • ….. would be unique • III. Development of LT Instrumentation • Exploit LT environment, High sensitivity measurements • low temperature electronics, high sens. NMR, NQR, SQUIDs • (frustrated magnets, heavy fermions ….) Sub-mK susceptibility studies Qu. Phase Transitions

9. 3 ft HTS Magnet Example Top View Physics High Bay