The University of Utah
Department of Physics & Astronomy at the University of Utah

A Bolt of Insight


In the western Utah desert, the Telescope Array sprawls across an area the size of New York City, waiting for cosmic rays. The facility detects the high-energy particles that collide with Earth’s atmosphere constantly; the cosmic rays trigger the 500-plus sensors once every few minutes.

PHOTO CREDIT: Famartin via Wikimedia Commons

While poring over data in 2013, Telescope Array physicists discovered a strange particle signature; the photon equivalent of a light drizzle punctuated by a fire hose. The array had unexpectedly recorded an extremely rare phenomenon - gamma rays, the highest-energy light waves on the electromagnetic spectrum, produced by lightning strikes that beam the radiation downward toward the Earth’s surface. Five years later, an international team led by the Cosmic Ray Group at the University of Utah has observed the so-called downward terrestrial gamma ray flashes (TGFs) in more detail than ever before.

The Telescope Array detected 10 bursts of downward TGFs between 2014 and 2016, more events than have been observed in rest of the world combined. The Telescope Array Lightning Project is the first to detect downward TGFs at the beginning of cloud-to-ground lightning, and to show where they originated inside thunderstorms. The Telescope Array is by far the only facility capable of documenting the full TGF “footprint” on the ground, and show that the gamma rays cover an area 3 to 5 km in diameter.

“What’s really cool is that the Telescope Array was not designed to detect these,” said lead author Rasha Abbasi, researcher at the High-Energy Astrophysics Institute and the Department of Physics & Astronomy at the U. “We are 100 times bigger than other experiments, and our detector response time is much faster. All of these factors give us the ability that we weren’t aware of - we can look at lightning in a way that nobody else can.”

The study published online on May 17 in The Journal of Geophysical Research: Atmospheres.

An Accidentally Perfect Laboratory

PHOTO CREDIT: photo courtesy of the Telescope Array collaboration. A Telescope Array Surface Detector and its neighbors, deployed in Utah’s west desert. The 507 detectors are arranged on a grid covering 700 square kilometers, about the same as the land area of New York City.

The work builds on a study published by the group last year that established a strong correlation between similar bursts of energetic particle showers detected between 2008 and 2013, and lightning activity recorded by the National Lightning Detection Network. The physicists were stunned.

“It was BOOM BOOM BOOM BOOM. Like, four or five triggers of the detectors occurring within amillisecond. Much faster than could be expected by cosmic rays,” said John Belz, professor of physics at the U and principal investigator of the National Science Foundation-funded Telescope Array Lightning Project. “We realized eventually that all of these strange events occurred when the weather was bad. So, we looked at the National Lightning Detection Network and, low and behold, there would be a lightning strike, and within a millisecond we would get a burst of triggers.”

The researchers brought in lightning experts from the Langmuir Laboratory for Atmospheric Research at New Mexico Techto help study the lightning in more detail. They installed a nine-station Lightning Mapping Array developed by the group, which produces 3-D images of radio-frequency radiation that lightning emits inside a storm. In 2014, they installed an additional instrument in the center of the array, called a “slow antenna,” that records changes in the storm’s electric charge caused by the lightning discharge.

PHOTO CREDIT: National Oceanography and Atmospheric Administration. The bright flash of light is only one stage of lightning; there’s a substructure that happens too fast for the eye to see. “Step leaders” proceed toward the ground in stages. Negative electric charge builds at the leader tip until it is sufficient to cause the air to break down and form a new conducting path. The study found that terrestrial gamma rays are produced within the first 1-2 milliseconds of the initial breakdown stage, which is the least understood part of lightning.

“Taken together, the Telescope Array detections and the lightning observations constitute a major advance in our understanding of TGFs. Prior to this, TGFs were primarily detected by satellites, with little or no ground based data to indicate how they are produced”, said Paul Krehbiel, long-time lightning researcher at New Mexico Institute of Mining and Technology and co-author of the study. “In addition to providing much better areal coverage for detecting the gamma rays, the array measurements are much closer to the TGF source and show that the gamma rays are produced in short duration bursts, each lasting only ten to a few tens of microseconds.”

An Extremely Rare Phenomenon

Until a FERMI satellite recorded the first TGF in 1994, physicists thought only violent celestial events, such as exploding stars, could produce gamma rays. Gradually, scientists determined that the rays were produced in the initial milliseconds of upward intracloud lightning, which beamed the rays into space. Since discovering these upward TGFs, physicists have wondered whether cloud-to-ground lightning could produce similar TGFs that beam downward to the Earth’s surface.

Previously, only six downward TGFs have ever been recorded, two of which came from artificially-induced lightning experiments. The remaining four studies with natural lightning report TGFs originating much later, after the lightning had already struck the ground. The array’s observations are the first to show that downward TGFs occur in the initial breakdown stage of lightning, similar to the satellite observations.

PHOTO CREDIT: Animation by John Belz, LMA data courtesy of Langmuir Laboratory, New Mexico Tech. An animation of cloud-to-cloud lightning (the circles) as detected by the Lightning Mapping Array (LMA) over the Telescope Array Surface Detectors (red squares). The color represents time – earliest LMA sources are in blue, and the latest in red. The entire event takes about one tenth of a second. The LMA is sensitive to what is happening thousands of meters above the ground.

“The downward-going TGFs are coming from a similar source as the upward ones. We safely assume that we have similar physics going on. What we see on the ground can help explain what they see in the satellites, and we can combine those pictures in order to understand the mechanism of how it happens,” said Abbasi.

“The mechanism that produces the gamma rays has yet to be figured out,” added Krehbiel.

What’s Next?

The researchers have many questions left unanswered. For example, not all lightning strikes create the flashes. Is that because only one particular type of lightning initiation produces them? Are the scientists only seeing a subset of TGFs that happen to be large enough, or point in the right direction, to be detected?

The team hopes to bring additional sensors to the Telescope Array to enhance the lightning measurements. In particular, installing a radio-static detecting “fast antenna” would enable the physicists to see the substructure in the electric field changes at the beginning of the flash.

“By bringing other types of lightning detectors and expanding the effort, I think we can become a significant player in this area of research,” said Belz.


This study resulted from a collaboration between 126 co-authors from 33 universities and research institutions from the United States, Japan, Korea, Russia and Belgium.. For a full list of co-authors, please refer to the study abstract.

The lightning mapping array used in this study was developed and operated with the support of the NSF Division of Atmospheric Sciences (AGS-1205727 and AGS-1613260). The Telescope Array experiment is supported by the Japan Society for the Promotion of Science through Grants-in-Aids for Scientific Research on Specially Promoted Research (15H05693) and for Scientific Research (S) (15H05741); the Inter-University Research Program of the Institute for Cosmic Ray Research; the United States NSF awards (PHY-0307098, PHY-0601915, PHY-0649681, PHY-0703893, PHY-0758342, PHY-0758320, PHY-1069280, PHY-1069286, PHY-1404495, PHY-1404502); the National Science Foundation of Korea (2015R1A2A1A01006870, 2015R1A2A1A150553344, 2016R1A5A1013277, 2007-0093860, 2016R1A2B4014967); the Russian Academy of Sciences (RFBR grant 16-02-00962a (INR), IISN project No. 4.4502.13); and the Belgian Science Policy under 1UAP VII/37 (ULB). The foundations of Dr. Ezekiel R. and Edna Wattis Dumke, Willard L. Eccles, and George S. and Dolores Doré Eccles helped with generous donations. The state of Utah supported the project through its Economic Development Board and the U supported through the Office of the Vice President for Research.

Read the full press release on the UNews website. The published paper, "Gamma-ray Showers Observed at Ground Level in Coincidence With Downward Lightning Leaders", is available on the Journal of Geophysical Research: Atmospheres website.



Christoph Boehme Receives Distinguished Scholarly and Creative Research Award

Dr. Christoph Boehme

Christoph Boehme has been awarded the University's Distinguished Scholarly and Creative Research Award. This is one of the University's highest faculty awards for teaching, and is well deserved. The Distinguished Scholarly and Creative Research Award is set aside for faculty with eight or more years of service as the University of Utah and recognizes outstanding teaching, innovative pedagogy, concern for students, and exemplary contributions to the educational process outside the classroom.

From the announcement:

"As a condensed matter scientist, Christoph Boehme has made ground-breaking discoveries that are fundamental to the next generation of electronic and computer technologies. “Professor Boehme is one of those rare experimental physicists who has developed new cutting-edge experimental techniques and devices, [whereby discovering] fundamental new physical phenomena in substances that are of great current practical and technological importance,” remarked a colleague. 'A common thread in his work is the use of elegant, innovative, and creative experimental techniques to reveal the most fundamental quantum properties of matter.' One of his most important breakthroughs was developing the pEDMR technique, a method for observing the quantum mechanical motion of charged electron spins in semiconductors. This has led to one of his multiple patents and has been instrumental in the development of new electronic and optoelectronic materials. He has published 93 papers in archival reference journals, and received multiple prestigious awards for his research, including a CAREER Award of the National Science Foundation and the silver medal in Best Physics Research from the International EPR Society. During Boehme’s 12 years at the U, he has supervised 28 postdoctoral, graduate and undergraduate students in their research. Professor Boehme’s creativity, productivity, and his impact on future technologies make him a deserving recipient of the Distinguished Scholarly and Creative Research Award."

Prof. Boehme was formally recognized for this achievement during University and College Commencement Exercises in May 2018.

The University Distinguished Scholarly and Creative Research Award honors significant contributions to the mission of the University of Utah. Click here to learn more and to see past recipients.

To learn more about the 2018 recipients, please click here.


2018 Department Awards & Scholarships

Graduation and commencement exercises for the University of Utah took place on May 3, 2018. The Department of Physics & Astronomy congratulates all of its 2018 graduates and welcomes them to their alumni family.

The Department of Physics & Astronomy also congratulates all its 2018 student award recipients on their hard work and accomplishments. Recipients were honored at the Physics & Astronomy Awards Ceremony on Tuesday, May 1st at 2:00 PM in the James Fletcher Building.

Congratulations to our 2018 graduates and scholarship recipients!
(* denotes Honors degree)

2018 Awards & ScholarshipsBaccalaureate DegreesMasters DegreesPh. D Degrees

Scholarship Recipients
Joshua Bromley
Connor Houghton
Maile Burnett Marriott
Kaitlin McLean

Paul Gilbert Outstanding Undergraduate Research Award
Teddy Anderson

Martin Hiatt Outstanding Undergraduate Research Award
Alisa Mann

David & Karen Imig Undergraduate Scholarship for Women
Rylee Cardon

Outstanding Undergraduate Sophomore Award
Jonah Barber

Outstanding Undergraduate Junior Award
Robert Stahulak

Outstanding Undergraduate Senior Award
Caleb Webb

Thomas J. Parmley Scholarship
Jade Aderibigbe
Megan Schneider

Tyler Soelberg Memorial Award
Jade Aderibigbe

Preston J. and Phyllis R. Taylor Undergraduate Award
Elom Amematsro

Walter Wada Scholarship for Undergraduate Physics Major
Galen Bergsten

Diversity Award
Flo Doval
Neda Lotfizadeh
Elom Amematsro

Irvin and Norma Swigart Scholarship
Megha Agarwal
Rajesh Malla
Ye Tian

Outstanding Graduate Student Award
Xiaojie Liu
Zhuxi Luo

Outstanding Graduate TA Award
Nathan Gundlach
Jason May

Outstanding Post-Doctoral Research Award
Hao Liang Liu

Students’ Choice Award for Undergraduate Seminar
Rich Ingebretsen
Christoph Boehme

Kyle Ahn
Matthew Bernstein
Joseph Blanton Isaac Buckland
Taylor Buckway
Haili Campbell
Benjamin Cantera
Tyler Crum
Elijah Forbes
Timothy Gannon
Glen Hamblin
Mark Hayward
Tyson Howes
Kamal Ibrahim
Isaac Johnson
Nels Jorgensen
Tyler Kaiser
Konstan Karpos
Sterling Leduc
Charles Lucas
Sean Martinson
Shalin Patel
Connor Pearrow
Joshua Peterson
Karli Rees
Robbie Robinson
Jeffrey Rodgers
Gregory Rutledge
Deric Session
James Skowronek
Shaun Snow
Mahdi Sofla
Sabastion Sorensen
Gregory Spencer
Cole Takasugi
Jesse Warner
Caleb Webb
Matthew Wilkinson
Sandip Aryal
Mykola Peshyn
Julia Russ
Xiatong Zheng
Christopher Ahn
Douglas Baird
Sangita Baniya
Thapa  Bijaya
Nathan Gundlach
Shirin Jamali
Gajadhar Joshi
Jon Paul Lundquist
Dieu Duc Nguyen
Lei Shan
Haojie Xu


Commencement & Convocation Information 2018

Commencement & Convocation Information 2018

From the Office of the Registrar & the College of Science


University Commencement will be held on Thursday, May 3, 2018 at 6:30pm in the Jon M. Huntsman Center (Map). Candidates for graduation in the summer 2017, fall 2017, spring 2018, or summer 2018 terms may attend.

Commencement is open to the public and free to attend. No tickets or RSVP required. This year's commencement speaker will be Ben Nemtin, star of MTV's "The Buried Life" and New York Time's best-selling author. Barbara Tanner and Raymond Uno will receive honorary doctorate degrees, the highest honor give by the university. Those who are unable to attend commencement can watch it streamed live on

For those of you attending or participating in graduation ceremonies this spring, here's some important information.


(For the entire campus where the VIPs speak)
Thursday, May 3, 2018
Jon M. Huntsman Center (Map)

  • 5:00 pm - Graduates assemble in the Parking Terrace west of the Huntsman Center dressed in cap and gown
  • 5:30 pm - Guests should be seated
  • 5:45 pm - Procession begins
  • 6:30 pm - Commencement ceremony begins


(Where your name is called and you walk across the stage)
College of Science (Click here for other colleges' date, time and location)
Thursday, May 3, 2018
Jon M. Huntsman Center (Map)
More info

  • 7:15 - 7:45 am - Graduates assemble outside Jon M. Huntsman Center (see the link above for additional details)
  • 9:00 am - Convocation ceremony begins
  • 11:00 am College of Science Reception - location TBA


Following the Convocation, graduates and their guests are invited to a reception for the College of Science Class of 2018. Details to be provided soon.


Convocation will also be streamed live online so forward these links to family and friends who want to view it, but can't attend:
On-demand streaming of the College of Science Convocation will be available here.
The live stream link will be available here.


Campus parking lots may be used at no charge during commencement and convocation ceremonies. Please see the commencement parking map for parking locations as well as shuttle and TRAX stops. Additionally, since campus parking is limited, we encourage the use of UTA TRAX on these days. The use of TRAX while on campus is free both days, but fare is still required for any off campus travel.

Shuttle Services

As campus parking is limited, graduates and their guests are encouraged to use the free campus shuttle service to travel between commencement events. Shuttles run throughout campus and are scheduled every 10 minutes. Track the current location of any campus shuttle using the Live Shuttle Tracker.

Accessible Parking

For a map to all accessible parking options on campus, visit the campus map and select the "Accessible" option from the Map Features drop-down menu.

Construction Alerts

For a map with notifications regarding all parking lots effected by campus construction, view the campus map and select the "Construction" option from the Map Features drop-down menu.

Commuter Services

For more information about transportation and parking options, visit the Commuter Services website.

To learn more, please visit the Commencement Ceremony Parking & Transportation page.


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