ORNL Neutron Times
Bimonthly News for HFIR and SNS Users   |   November—December 2022

A Message from Ken Andersen

I’d like to wish everyone in our wide and varied user community a joyous holiday season and a Happy New Year. It’s a privilege and an honor for me to serve as Associate Laboratory Director for Neutron Sciences here at Oak Ridge National Laboratory, overseeing two of the world’s most productive and impactful neutron sources, the High Flux Isotope Reactor (HFIR) and the Spallation Neutron Source (SNS).
We continue to deliver cutting-edge science while planning for the future. The lab has made tremendous progress on critical projects, including the Proton Power Upgrade and the Second Target Station, which will necessitate a reduction in the amount of beamtime we can deliver at SNS over the next two years, as we install the required accelerator upgrades. The HFIR Beryllium Reflector Replacement activities are moving ahead rapidly and the VENUS imaging instrument is starting to take real, concrete shape at SNS. These major facility upgrades will deliver wholly new scientific capabilities and increase the global impact of SNS and HFIR science. And ORNL continues to focus on maximizing the benefit to our users, including making further improvements to our data pipeline, expanding our neutron scattering applications with various initiatives for developing new techniques and better sample environment equipment, continuing to invest in instrument upgrades, and prioritizing new, innovative tools for data analysis and analytics. 
We look forward to continuing our collaboration with you in 2023, using the unique properties of neutrons to develop new materials and technologies and to address some of the most pressing scientific challenges ahead.

SNS-HFIR User Group (SHUG) Executive Committee (EC) Election Results

Three new general members have been elected to the SHUG Executive Committee starting January 1, 2023. The newly elected SHUG EC members are Benjamin Frandsen (Brigham Young University), Mingda Li (Massachusetts Institute of Technology), and Julia V. Zaikina (Iowa State University). They will join returning members Rana Ashkar, Rebecca Dally, Lisa Debeer-Schmitt, Peter Gilbert, Yun Liu, Naresh Osti, Travis Williams, Amy Xu, and Igor Zaliznyak. Igor Zaliznyak will assume responsibilities as the SHUG chair January 1, 2023.
Many thanks to Yun Liu for serving as the 2022 SHUG EC Chair, and to outgoing SHUG EC members who have served for the past three years: Adrian Brügger, Geneva Laurita, and Daniel Shoemaker.
In 2023, the SHUG EC plans to continue the breakthrough symposium series, and to host an in person user meeting. If you would like to suggest topics or speakers, please contact the SHUG EC at shug-ec@email.ornl.gov.
New SHUG Executive Committee members from left to right:
Benjamin Frandsen, Mingda Li, and Julia V. Zaikina

Multi-Factor Authentication for SNS and HFIR Remote Instrument Access

User Office
As part of ORNL’s continuing efforts to protect the security of data and the Lab, we will be piloting multi-factor authentication (MFA) in 2023 for external users remotely logging into SNS and HFIR resources. This includes users who are only participating remotely (not coming onsite) as well as onsite visitors who want access to remote beamline functions.
This will be a phased rollout and impacted users will be notified in advance with instructions for identity vetting and the set-up of second-level credentials. Users who receive this notice should follow the steps for creating a profile in the Microsoft Authenticator app and logging in remotely to the beamline.

Foreign National Users Arriving from Outside the U.S. Must Have a Visa Waiver – Business or B-1 Business Visa Status

We have continued to see an increase in users arriving at ORNL with the incorrect visa status. To participate in research at ORNL, individuals traveling from outside the U.S. must enter the U.S. with either a Visa Waiver-Business (VWB) or B-1 Business Visa status. Most U.S. Customs and Border Protection offices are no longer stamping passports, and instead will direct travelers to a self-service kiosk. You will need to ensure that you have received a VWB or B-1 status for your visa paperwork. If you do not receive a stamp or printout from the kiosk, you can utilize this website https://i94.cbp.dhs.gov/I94/#/home to look up your status prior to leaving the Port of Entry. If your status shows anything other than a VWB or B-1 status, you will need to ask the immigration officer to correct this for you before you leave.

If you arrive at ORNL with the incorrect visa status, you will have to either drive or arrange for a taxi to take you to the downtown Knoxville Customs office to get it corrected. This can lead to delays in completing on-site training and/or experiment participation. Please be sure to double check your visa status prior to leaving the U.S. Port of Entry, to avoid any delays upon your arrival at ORNL.

General User Proposal Call Updates

Call for Proposals
The Neutron Sciences General User Proposal Call 2023-A closed on September 21, 2022, and award letters were sent November 15. In the 2023-A proposal call, SNS received 581 beamtime requests; 175 were approved and 162 placed in Alternate status. HFIR received 275 beamtime requests; 92 were approved and 77 placed in Alternate status. Results are summarized on the Proposal Statistics webpage.
The 2023-B General User Proposal Call deadline is Wednesday, February 22, 2023, at Noon (Eastern), for HFIR experiments expected to run between August and December 2023.

Due to the planned Proton Power Upgrade (PPU) outage starting in August 2023, SNS instruments will not be accepting proposals in the 2023-B or 2024-A proposal calls. The current HFIR/SNS 5-Year Working Schedule expects SNS availability to resume July 2024, contingent on PPU progress.

Career Opportunities Available at SNS and HFIR

Apply Now
National labs like ORNL are distinguished by their ability to assemble large teams of experts from a variety of scientific and technical disciplines to tackle compelling national problems. They also design, build, and operate powerful scientific facilities such as SNS and HFIR that are available to the international research community. If you are passionate, creative, and collaborative, ORNL offers the opportunity to build an impactful career with like-minded peers. Visit https://jobs.ornl.gov/ to view current openings.
Upcoming opportunities in the Neutron Sciences Directorate include:
Postdoctoral Research Associates (Requisition ID 9170)
Group Leader for Chemical Spectroscopy (Requisition ID 9238)
HFIR Scientific Associate (Requisition ID 9084)

Changes to User Check-In

SNS User Check-In
After reporting to the Chestnut Ridge Visitors Center at SNS to pick up your badge, users will need to report to the User Assistant on duty to verify training is complete and/or scheduled, and to pick up a dosimeter.

Sample check-in for SNS is now located in 8600, Room K-202 (located around the corner from the previous Experiment Check-In Office in K-201). Sample Check-In for HFIR has remained the same, located in the Cold Guide Hall next to beamline CG-3.

Science Highlight

The Building Blocks for Exploring New Exotic States of Matter

The research team, led by scientists from the University of California, Los Angeles, developed the intrinsic ferromagnetic topological insulator by making a compound with alternating layers of MnBi2Te4 and Bi2Te3, bonded by weak interlayer forces of attraction between molecules. Scientists recently discovered that MnBi2Te4 is a naturally magnetic topological material. However, when layers of magnetic MnBi2Te4 are directly stacked on one another, the magnetic moments within neighboring layers point in opposite directions, making the material antiferromagnetic as a whole – losing the topological aspects of the properties that are important for technologies. The researchers solved this problem by making a new compound with three nonmagnetic layers of Bi2Te3 between layers of MnBi2Te4, which, combined, creates MnBi8Te13. This material design increases the distance between the MnBi2Te4 layers, which successfully eliminates the antiferromagnetic effect, leading to long-range ferromagnetism below 10.5 K with strong coupling between magnetism and charge carriers.

Important aspects of this research were neutron scattering experiments through the DEMAND instrument at the High Flux Isotope Reactor that pinpointed how atoms are arranged within the MnBi8Te13 material and confirmed its ferromagnetic state. Because neutrons have their own magnetic moment, they can be used to determine the magnetic structure inside a material. The scientists additionally used angle resolved photoemission spectroscopy experiments at the Stanford Synchrotron Radiation Lightsource, a Department of Energy user facility, and first-principles, density functional theory calculations to investigate the material’s electronic and topological state. Combining the assessments from all of these methods, the researchers were able to validate the ferromagnetic and topological properties consistent with an axion insulator with sizable surface hybridization gaps and a nontrivial Chern number. Read the full article here.

Visit our Neutron Science News and Highlights page for all the recent news and features.

Instrument Highlight

New Sample Environment Capability at Bio-SANS

Bio-SANS, a world-class small angle neutron scattering instrument specializing in performing experiments on biological materials, has launched a new sample environment capability.

Bio-SANS sample environment
A system combining Size-Exclusion Chromatography and Small-Angle Neutron Scattering (SEC-SANS) has recently been commissioned at the Bio-SANS beamline. The setup, which consists of an autosampler, an ÄKTA Pure HPLC, and a SANS flow cell, has been designed to allow experiments in either continuous-flow or fractionation mode to provide more accurate SANS measurements on freshly purified macromolecules and their complexes, which will especially benefit aggregation-prone samples.
The current setup features four demountable flow cells for peak fractionation and simultaneous UV-Vis spectroscopic monitoring of up to three wavelengths (between 190 to 700 nm). Including this capability improves monitoring of the chromatographic profile of biomacromolecules (i.e. RNA or DNA) or protein-nucleic acid complexes. To learn more about this and other Bio-SANS sample environments, please contact the CSMB team at csmb@ornl.gov.

New Staff

Please welcome Gaurav Vishwakarma as a new postdoctoral fellow working with Christina Hoffmann, in the Single Crystal Diffraction group in the Neutron Scattering Division.  Prior to joining ORNL, Gaurav completed a PhD in Theoretical Chemistry, mentored by Prof. Johannes Hachmann, at the University at Buffalo this summer. His research was focused on discovering novel molecular catalysts for fuel cell systems based on liquid organic hydrogen carriers, where the approach involved a combination of high throughput first-principles calculations along with state-of-the-art data analysis and machine learning techniques.
Outside of work, Gaurav enjoys engaging in social activities, exploring adventure trails, and is a passionate chess and badminton player.
Rohit Srivastava has joined the User Programs & Outreach Group in the Neutron Scattering Division as a Data Analyst. Prior to joining NScD, Rohit worked as a Data Services Engineer in the Data Lifecycle and Scalable Workflows group in the Computing and Computational Sciences Directorate. Rohit holds a master’s degree in Information Sciences and a bachelor’s degree in Chemistry from the University of Tennessee in Knoxville. 
Outside of work, Rohit likes to spend his free time watching sports, whether it’s on TV or at UT, and going to trivia at least once a week. He also enjoys attending the numerous festivals that come to downtown Knoxville every year.
For questions or comments about this newsletter, please contact
Janell Thomson thomsonji@ornl.gov.
Copyright © 2022 Neutron Sciences at ORNL, All rights reserved.

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