Young Professionals introduces outstanding young professionals (under 40 years of age) who are doing interesting things in cryogenics and superconductivity and who show promise of making a difference in their fields. Debuted in the Summer 2006 issue, the feature has presented many young persons whom we are proud to see have indeed lived up to that promise.

Rudra Pratap, 27
My educational and professional background: I earned my B.Tech in mechanical engineering from Gitam University, Visakhapatnam, India, and am currently pursuing my PhD in materials science and engineering at the University of Houston.

How I got into cryogenics: Modern technology has always attracted me. In my undergraduate days, I used to go through several science and technology-based websites to keep myself updated on new and innovative technologies. I came across the concept of superconductivity and its application in experiments at CERN. When I joined the University of Houston for my masters, I came across a course on superconductivity that took me into the world of superconductivity and cryogenics.

I was fortunate to be accepted by Dr. Venkat Selvamanickam in his group as a PhD student to work on the growth of High Temperature Superconductor (HTS) films, their characterization and optimization, where I am getting hands-on experience in cryogenics and superconductivity.

My mentor and my experience with him/her: Regarding mentors, I believe in the saying of Buddha: “Everyone else is your teacher.” I consider myself very fortunate to have had exceptional mentors at different stages of my life and career—my parents, teachers, friends, seniors and colleagues.

Specific to cryogenics, two people have been instrumental in my development as a professional: Dr. Venkat Selvamanickam, my PhD advisor, and Dr. Goran Majkic, research associate professor and colleague. I was introduced to the field of superconductivity and cryogenics by my advisor, Dr. Selvamanickam, who has given me guidance, support, knowledge and freedom to grow in this field.

He has provided me with challenging opportunities and responsibilities to work on several different superconducting projects, which has improved me both as a person and a professional.
He introduced me to another genius, Dr. Majkic, under whom I got most of my technical training. With his abundance of knowledge, technical prowess and a great passion towards research he has been the guiding light during my PhD research.

In addition to getting technical expertise from both, I have also learned the value of proper work ethics, time management, discipline, patience and passion required to achieve the desired goal.

Awards/honors:
– Selected as one of the young scientists among six in the superconductivity field and invited to give a talk on “Challenges and advances in thick film REBCO tapes” at the young scientist plenary session held at the Applied Superconductivity conference 2018, Seattle

-Second place winner at TcSUH 54th Semiannual Symposium. Presented an oral talk on “Development of high performance thick Zr-added (Gd,Y)BCO tapes using advanced MOCVD”

– Appreciation award to my team by NASA at 3rd Lunabotics International Mining Competition held at Kennedy Space Center, FL, for developing an innovative and cost efficient Lunar Rover to operate on synchronized regolith

My contributions to the cryogenic field: Most of my work has been focused on growing high performance thick REBCO (Rare Earth Barium Copper Oxide) superconducting films by using inhouse-built advanced MOCVD (Metal Organic Chemical Vapor Deposition).

The major bottleneck in the commercialization of second generation superconductors, specifically REBCO, has been the high cost/performance of these materials. This high cost/performance has been associated with the high precursor cost and the limitation of making high performance thicker REBCO films over 1-2μm. The inability to make thicker films is due to the lack of proper control in composition and processing conditions. In this regard, we have been able to successfully optimize compositions, processing conditions and hardware to grow very high performance, over 4-5μm thick doped and undoped REBCO films. These REBCO films have 4X times higher whole engineering current density than Nb3Sn at 4.2 K, 14T (B parallel C).

In addition, I have worked on investigating and optimizing dopant concentrations and compositions of these thick REBCO films for different temperature (77 K-4.2 K) and field (up to 13T)
applications.

Very recently, we have also worked on improving the precursor to film conversion efficiency of advanced MOCVD from a mere 15% to 45%, which cuts down our production cost. However, there is still a long way to go to make these tapes in long lengths for commercial use. We are currently focused on this because we believe high performance, long length thick REBCO film has the potential to contribute towards a better, brighter and greener future.

What are the most important developments in cryogenics? Cryogenics has been a true game-changer in applications of modern superconducting technology. NMR, MRI, superconductors’ electrical distribution, high field magnets, accelerator magnets are few of the many technologies that are directly impacted by cryogenics. For me, superconducting magnet technology has been one of the most important developments.

My current work is focused on making long length thick REBCO films with very high current carrying capability which will certainly pose challenges in its application. I hope in the near future, with the rapid advancement in cryogenics, we will be able to use our tapes for different superconducting applications.

What advances do you hope to see in the future? At this point in time, when everyone is looking at High Temperature Superconductor (HTS) tapes for future superconductivity applications such as high field fusion applications, HTS cables, HTS motors and generators, etc., I really hope it turns into a reality. There are still some major concerns such as cost, tape uniformities, quench, etc., which need to be taken care of. I think it might take a decade more to achieve these advances.

Where can readers find out more about your projects? Readers can find out about my research papers and projects either on Linkedin at www.linkedin.com/in/rudra-pratap-34211042/ or on research gate at www.researchgate.net/profile/Rudra_Pratap2

Brandt Pedrow, 28
My educational and professional background: A BS from the University of Idaho in mechanical engineering, and a MS from Washington State University also in mechanical engineering.

How I got into cryogenics: I always enjoyed thermodynamics and heat transfer classes in my undergrad studies. It was a natural jump in my mind to move to cryogenics, where these two specialties were of the utmost importance. Plus, ridiculously cold things are awesome!

My mentor and my experience with him/her: Jake Leachman, a professor at Washington State University (CSA 2018 Boom awardee), was my advisor there and I would very much consider him a mentor from that time. He took a hands-off approach that I enjoyed in my research, allowing me to find my way through the world of cryogenics, but still providing the last little hint or help when I got stuck by some problem. He has a way of looking at problems from a unique viewpoint different from many other people, so it was good experience for me to be able to interact with Jake and really figure out how he works and try to apply that myself.

My present company/position: Fluid Systems Engineer at Blue Origin.

My contributions to the cryogenic field: From a research perspective, my master’s thesis was based on looking into the practicality of using hydrogen boiloff gas along with a catalyst to passively increase its cooling capacity as a vapor cooling for warmer cryogenics. This has specific applications for space travel, where cryogenic fluids are advantageous but have the issue of long-term storage.

Other contributions I have made towards the field of cryogenics are in the area of practical usage, specifically, my work at Blue Origin and the sub-orbital, re-usable, New Shepard program. I help develop, test and improve parts within our cryogenic system to ensure consistent quality and reliability, something exceedingly important in a system that goes through extreme environments many times across its lifetime.

What are the most important developments in cryogenics? I believe that extreme reductions in cryogenic boiloff in space is an important advancement to help with long-term human space travel if we want to continue using these as propellants in conventional rocket engines. This can be achieved through both active and passive measures, and likely will end up using concepts from both as we move forward.

Where can readers find out more about your projects? I have no social media handles to actively promote the field myself, however my past work and projects from graduate school can be found at https://hydrogen.wsu.edu.

And while there isn’t any direct showcasing of my work individually, more information about Blue Origin’s rockets can be found at www.blueorigin.com.

Ian Richardson, 29
My educational and professional background: BSME 2011; PhD 2017-material science engineering–“Characterizing Dissolved Gases in Cryogenic Fuels”; Background–cryogenic experiment design, construction and operation.

How I got into cryogenics: I started working as an undergraduate in the Hydrogen Properties for Energy Research (HYPER) laboratory at Washington State University in 2010 under Professor Jacob Leachman. After getting my feet wet in research, I decided to stay on as a graduate student and my first project was designing a cryostat to accommodate a dual sinker densimeter in order to conduct density measurements on liquid hydrogen mixtures.

My mentor and my experience with him/her: Professor Jacob Leachman first introduced me to the field of cryogenics and has been a mentor ever since. In the early days of the lab, money was tight, so we had to get creative with our designs. Jake and I would often go back and forth with design revisions until we got to something we were pretty sure would work. If it didn’t, we’d go back to the whiteboard to figure out how we were going to fix it. Jake has maintained and fostered this creative environment over the years as the lab continues to grow.

My present company/position: Protium Innovations LLC—co-founder: Leading the development efforts on transportable hydrogen fueling systems utilizing liquid hydrogen for aerospace applications as well as high pressure gaseous systems for ground-based fuel cell vehicles.

Awards/honors:
– Grand Prize Winner—2014 Hydrogen Student Design Contest to Design a Drop-in Hydrogen Fueling System—Team Leader
– NASA Space Technology Research Fellow 2014
– Klaus and Jean Timmerhaus Scholarship Award—Cryogenic Engineering Conference 2015
-Washington Research Foundation Postdoctoral Fellow—2018

My contributions to the cryogenic field: In 2014, I retrofitted a densimeter to conduct pressure-density-temperature-composition measurements on cryogenic fluid mixtures. This was the only experiment in the world capable of conducting fluid density measurements below temperatures of 90 K. This system was developed to conduct density measurements of helium pressurant in liquid hydrogen to simulate the conduction of liquid hydrogen rocket propellant for NASA. I then modified the system to conduct pressure-density-temperature-composition measurements on methane-ethane-nitrogen mixtures to simulate the seas of Saturn’s moon Titan.

From there I have gone on to develop experiments to simulate effervescence due to heating of a submarine in the methane-ethane rich seas of Titan and to develop a cryogenic thermal conductivity experiment to analyze printed materials and insulation at cryogenic temperatures.

I am now working to commercialize transportable hydrogen fueling systems and liquid hydrogen fuel tanks.

What are the most important developments in cryogenics? In my admittedly biased opinion, the recent investments in liquid hydrogen infrastructure and transportation by Japan, the EU, and California pose a great opportunity for advancements in the field. I have tailored my work to provide small-scale, transportable hydrogen liquefaction and fueling stations to accelerate the adoption of hydrogen.

The hydrogen stations I am working to commercialize provide short-term solutions to increase the hydrogen demand until it reaches a level where installing a large-scale system is economical.

What advances do you hope to see in the future? I hope to see the use of cryogens and cryogenics in our everyday lives. We are already seeing this in the cryogenic cocktails and celebrity chef “cooking” with LN2. Increased awareness will alleviate some of the public’s preconceptions and fears about cryogenics, and hydrogen specifically, which will hopefully lead to additional support in terms of research and infrastructure development.

Where can readers find out more about your projects? Additional information about Protium Innovations LLC can be found at: https://protiuminnovations.com.

Additional information regarding research being conducted at the HYPER lab can be found at: https://hydrogen.wsu.edu.

Olivia Chen, 32
My educational and professional background: I completed my PhD study in applied superconductivity in 2017 at Yokohama National University, Japan, where I now work as an assistant professor at the Institute of Advanced Sciences. My research includes superconducting electronics, extremely high energy-efficient computing, deep learning hardware accelerator and design automation for superconducting VLSI implementation.

How I got into cryogenics: Before starting my PhD study, I worked with a semiconductor company, where I developed an interest in CMOS technology.

My journey with cryogenics began after getting accepted by my PhD supervisor Prof. Nobuyuki Yoshikawa, who has the largest research group of superconducting electronics in the world.

My mentor and my experience with him/her: Prof. Yoshikawa guided me into this low-temperature world. He is a great mentor who always helps his students reach their full potential by not only providing knowledge but also respecting their ideas and letting them explore by themselves.

Awards/honors:
– JGC-S (Nikki-Saneyoshi) scholarship (2013)
– SNF preprint paper (2017)
– Invited talk at young scientist plenary session of 2018 Applied Superconductivity Conference (2018)

My contributions to the cryogenic field: During 2012-2014, I was engaged in research on single-flux-quantum (SFQ) circuits using superconducting electronic technology. I have successfully demonstrated an SFQ-based computing system for exploring an unsolved mathematical problem—Collatz conjecture,” using a superconducting integrated circuit process with a minimum linewidth of 1 μm.

In 2014, I began research on adiabatic quantum-flux-parametron (AQFP), an adiabatic superconductor logic that has been proposed as an alternative to CMOS logic with extremely high energy efficiency. My contributions include the development of the AQFP digital cell library, proposal of an AQFP specified synthesis framework, as well as the successful demonstrations of some AQFP-based implementations such as decoders and register files.

I have also been involved in the IARPA SuperTools project since 2017, whose goal is to develop an open source superconductor-specified CAD suite to achieve breakthroughs in superconducting VLSI fabrication.

What are the most important developments in cryogenics? I believe that one of the most important developments in cryogenics is superconducting digital electronics. Low-power superconductor logics—e.g. AQFP, RQL, eSFQ, ERSFQ—are capable of building future high-end computing systems with a working speed of several tens of gigahertz and thousands of times of lower power consumption when comparing to CMOS.

In 2018, I proposed and demonstrated the first comprehensive superconducting deep learning accelerator using AQFP technology. The energy dissipation of this design is 6.23aJ per clock cycle, and the operating clock rate is 5GHz, rendering an ultrahigh energy efficiency of 10.1 PetaOPS/W (1.01 OPS/W) in MAC operations with bit-sequence length 256 (for a single input/weight), around three to four orders of magnitude higher than CMOS. This is a first step towards introducing adiabatic superconducting technology to AI applications.

What advances do you hope to see in the future? A breakthrough in VLSI superconductor circuit scale is highly desirable. In 5 to 10 years, with the benefit of the development of CAD tools for superconducting digital design, it is reasonable to expect that the scale of superconductor implementations will include millions or hundreds of millions of components on a single chip.

Where can readers find out more about your projects? Readers can find more information about me via oliviachen.info.

Daniel Cunnane, 35
My educational and professional background: I did my undergraduate work at the University of Pittsburgh in physics and mathematics, and my PhD at Temple University in Philadelphia under the tutelage of Dr. Xiaoxing Xi. The topic of my thesis was MgB2 Josephson Junctions for digital applications. I did end-to-end design, fabrication, and characterization of junctions and circuits.

Since then I have moved on to working on IR detectors for space applications, first Far IR heterodyne detectors and now direct detectors as well. I continue significant research into MgB2 thin films and devices, but other High Temperature materials like YBCO, as well as some lower temperature materials working with the superconducting kinetic inductance effect.

How I got into cryogenics: I remember the concept of superconductivity from grade school years. I did not understand the physics, but nonetheless enjoyed the macroscopic evidence, zero DC resistance, of the quantum physical effect, electron pairing.

During graduate school a promising professor joined the faculty and I decided to engage with him. His group specialized in superconductivity and I eventually wrote my thesis and earned my PhD in his group.

My mentor and my experience with him/her: I prefer to find a mentor no matter where I am in my life. There is always a next step or bigger goal and always someone to learn from to get there. I consider both my PhD advisor, Xiaoxing Xi, and my post-doctoral advisor and current co-worker, Boris Karasik, to be mentors to me. I look up to them and they both show incredible character outside their expertise in the field. I feel honored that so many people I get to work with on a daily basis are people I look up to and admire both professionally and personally.

My present company/position: NASA Jet Propulsion Laboratory/microdevices engineer.

Awards/honors:
– Most recently I was honored to give a Young Scientists Plenary Talk at the Applied Superconductivity Conference in Seattle WA.
– I was awarded the Nancy Grace Roman Technology Fellowship from the NASA astrophysics program.

My contributions to the cryogenic field: In my decade of research, I have worked mostly on the novel superconductor, MgB2. The moderate critical temperature of ~40 K and the metallic properties of the material imply that it will serve well for superconducting electronics applications. The material offers near state-of-the-art performance in devices that can take advantage of existing state-of-the-art space cryogenic technologies. The most prominent of these technologies is as a THz Mixer for astrophysics applications.

I have recently delved into novel devices like Kinetic Inductance Bolometers (KIBs), which utilize the non-linearity of the superconducting kinetic inductance effect with the strong response of a bolometer. The device may be useful for an array of remote sensing applications and offers the array capability of a Kinetic Inductance Detector with the sensitivity of a bolometer. These devices can operate at a range of temperatures utilizing different materials to achieve the necessary noise for background limited measurements.

For example, YBCO KIBs (with a critical temperature of 90 K) can potentially operate in the 50 K range for observing outer solar system objects from a passively cooled space instrument.

What are the most important developments in cryogenics? Remote sensing space applications require unique developments for cryogenic coolers. MgB2 devices require 20 K or lower temperatures for competitive performance metrics and, while space cryocoolers exist that can achieve this temperature, improved efficiency and performance of such coolers are an important near-term goal.

What advances do you hope to see in the future? I would love to see a place solidify for MgB2 in superconducting electronics. There are many potential benefits of the material, but at the current time, maturation in thin film technology is needed for widescale adoption of the material. I hope to see wafer scale thin films with good uniformity over the next few years, which would increase application feasibility.

Where can readers find out more about your projects? Although working at JPL makes it slightly more difficult than an academic position for publication of my work. I hope that I can maintain a career where publications accurately represent the work I am doing. https://scholar.google.com/citations?user=OQDB_y4AAAAJ&hl=en

Taekyung KI, 37
My educational and professional background: I completed my PhD in mechanical engineering in 2013 at KAIST (Korea Advanced Institute of Science and Technology). I was a cryogenic postdoc fellow at Lawrence Berkeley National Laboratory to design: a. cryogenic cooling system for a superconducting undulator, b. helium liquefaction and recovery system for superconducting magnets, and c. electromagnet for the COSMIC magnet. I then worked at KEK (High Energy Accelerator Research Organization in Japan) as an assistant professor to design cryogenic transfer lines and cooling systems for a COMET (Coherent Muon to Electron Transition) project.

How I got into cryogenics: I was interested in thermodynamics and heat transfer. When I enrolled as a graduate student at KAIST, Prof. Sangkwon Jeong, my PhD advisor, introduced me to cryogenics and cryogenic engineering. I was attracted to unique fields and amazed by various applications.

My mentor and my experience with him/her: Prof. Sangkwon Jeong has been my mentor. When I was a graduate student, he gave me a lot of motivation and advice for my research and enthusiastically advised my PhD dissertation. He encouraged me to think creatively and to do outstanding research on pulse tube cryocoolers and other cryogenic cooling systems.

Prof. Toru Ogitsu-san at KEK also encouraged me to start research on cryogenic systems and gave me great support. He also helped me establish my orientation to research.

My present company/position: I am a leader of the cryogenic group at IBS (Institute for Basic Science) of South Korea, working on the development of cryogenic systems—two cryoplants, cryogenic distribution systems, and two superconducting radio frequency test facilities—for the RAON Heavy Ion Accelerator.

Awards/honors:
– Selected as Post-Doctoral Fellow by National Research Foundation of Korea, 2015
– Best basic research awarded by Korea government Ministry of Education, Science and Technology, 2012

My contributions to the cryogenic field: In South Korea, we are building the RAON Heavy Ion Accelerator that requires large cryogenic and superconducting systems. I am responsible for developing the cryogenic systems, which will be one of the largest (helium applications) in Asia. I am trying to increase the demand for and understanding of cryogenic cooling technologies related to accelerators in Asia. The design stages of systems will be completed this year, after which I will focus on the development of control logic and simulation models. I hope to make contributions to large cryogenic cooling systems.

At KAIST, I developed an efficient on-board pulse tube cryocooler for an HTS motor. My work was honored by the South Korean government. Also, my PhD research covered shows 1. “energy flows in pulse tube cryocoolers increase understanding of behaviors of helium and heat transfer” and 2. “a step-by-step design method for efficient pulse tube cryocooler.” My research added to the understanding of the design and phenomena of pulse tube cryocoolers.

What are the most important developments in cryogenics? Helium refrigerators/liquefiers/cryocoolers are the most important developments in cryogenics. The technologies help scientists and engineers do their research and make new developments easily and economically. Cryogenic cooling technologies are essential for basic science research and future technologies (accelerators and nuclear fusion) that can make enormous changes in life.

What advances do you hope to see in the future? I hope to see the development of a helium refrigerator/cryocooler with very high efficiency/reliability/stability to help researchers for big sciences and make it easy to apply superconducting systems. To realize them, more research is necessary for optimization of cycles and components. Also, more companies, universities and institutes need to collaborate in research.

Where can readers find out more about your projects? I am available at tyki0615@ibs.re.kr if you want to find out more about my work.