- Press Release Distribution

Mathematical model provides bolt of understanding for lightning-produced X-rays

Mathematical model provides bolt of understanding for lightning-produced X-rays
( UNIVERSITY PARK, Pa. — In the early 2000s, scientists observed lightning discharge producing X-rays comprising high energy photons — the same type used for medical imaging. Researchers could recreate this phenomenon in the lab, but they could not fully explain how and why lightning produced X-rays. Now, two decades later, a Penn State-led team has discovered a new physical mechanism explaining naturally occurring X-rays associated with lightning activity in the Earth’s atmosphere. 

They published their results on March 30 in Geophysical Research Letters. 

The team’s finding could also shed light on another phenomenon: the small shock sometimes felt when touching a metal doorknob. Called spark discharge, it occurs when a voltage difference is created between a body and a conductor. In a series of lab experiments in the 1960s, scientists discovered that spark discharges produce X-rays — just as lightning does. More than 60 years later, scientists are still conducting lab experiments to better understand the mechanism underpinning this process.  

Lightning consists in part of relativistic electrons, which emit spectacular high-energy bursts of X-rays with tens of mega electron-volt energies called terrestrial gamma-ray flashes (TGFs). Researchers have created simulations and models to explain the TGF observations, but there is a mismatch between simulated and actual sizes, according to lead author Victor Pasko, Penn State professor of electrical engineering. Pasko and his team mathematically modeled the TGF phenomenon to better understand how it can occur in observed compact space.  

“The simulations are all very big — usually several kilometers across — and the community has difficulty reconciling this right now with actual observations, because when lightning propagates, it's very compact,” Pasko said, explaining that lightning’s space channel is typically several centimeters in scale, with electric discharge activity producing X-rays expanding around tips of these channels up to 100 meters in extreme cases. “Why is that source so compact? It’s been a puzzle until now. Since we’re working with very small volumes, it may also have implications for the lab experiments with spark discharges underway since the 1960s.”

Pasko said that they developed the explanation for how an electric field amplifies the number of electrons, driving the phenomenon. The electrons scatter on individual atoms, which constitute the air, as they experience acceleration. As the electrons move, most of them go forward as they gain energy and multiply, similar to a snow avalanche, allowing them to produce more electrons. As the electrons avalanche, they produce X-rays, which launch the photons backward and produce new electrons.

“From there, the question we wanted to answer mathematically was, ‘What is the electric field you need to apply in order to just replicate this, to launch just enough X-rays backwards to allow amplification of these select electrons?’” Pasko said. 

The mathematical modeling established a threshold for the electric field, according to Pasko, which confirmed the feedback mechanism that amplifies the electron avalanches when X-rays emitted by the electrons travel backward and generate new electrons.

“The model results agree with the observational and experimental evidence indicating that TGFs originate from relatively compact regions of space with spatial extent on the order of 10 to 100 meters,” Pasko said.

In addition to describing high-energy phenomena related to lightning, Pasko said the work may eventually help to design new X-ray sources. The researchers said they plan to examine the mechanism using different materials and gases, as well as different applications of their findings. 

The other authors on the paper are Reza Janalizadeh, a postdoctoral scholar in the Penn State Department of Electrical Engineering; Sebastien Celestin of the University of Orleans in Orleans, France; Anne Bourdon, of Ecole Polytechnique in Palaiseau, France; and Jaroslav Jansky of the University of Defense in Brno, Czechia. 

The National Science Foundation funded this work.  


[Attachments] See images for this press release:
Mathematical model provides bolt of understanding for lightning-produced X-rays Mathematical model provides bolt of understanding for lightning-produced X-rays 2 Mathematical model provides bolt of understanding for lightning-produced X-rays 3


nTIDE March 2023 Deeper Dive: Intersection of race and disability perpetuate inequalities in employment impacting Black/African American people with disabilities

nTIDE March 2023 Deeper Dive:  Intersection of race and disability perpetuate inequalities in employment impacting Black/African American people with disabilities
East Hanover, NJ – March 31, 2023 – Since the pandemic, gains in the labor market have been slower to materialize for black/African American people with disabilities compared to their white counterparts, according to experts speaking last Friday during the nTIDE Deeper Dive Lunch & Learn Webinar. They discussed potential factors underlying why the disability employment gap is wider among members of the black/African American population when compared to the white population and how to integrate measures to effect change. Using data from the U.S. Bureau of Labor Statistics (BLS) for persons ages 16-64, the monthly employment-to-population ratio averaged ...

Researchers uncover the first steps driving antibiotic resistance

Antibiotic resistance is a global health threat. In 2019 alone, an estimated 1.3 million deaths were attributed to antibiotic resistant bacterial infections worldwide. Looking to contribute a solution to this growing problem, researchers at Baylor College of Medicine have been studying the process that drives antibiotic resistance at the molecular level. They report in the journal Molecular Cell crucial and surprising first steps that promote resistance to ciprofloxacin, or cipro for short, one of the most commonly prescribed antibiotics. The findings point at potential ...

Study reveals new insights into body salt handling

HUNTINGTON, W.Va. – A new study led by Marshall University researchers focuses on a novel mechanism of the body’s regulation of salt balance. The kidney plays a central role in the body’s ability to maintain an appropriate sodium balance, which is critical for the determination of blood pressure. Disorders of sodium balance contribute to the development and progression of many common diseases, including hypertension, heart disease and stroke.  Na/K-ATPase (NKA) is the enzymatic machinery that drives absorption of sodium along the renal proximal tubule. As ...

A tighter core stabilizes SARS-CoV-2 spike protein in new emergent variants

A tighter core stabilizes SARS-CoV-2 spike protein in new emergent variants
UNIVERSITY PARK, Pa. — Just as a tight core is a component of good physical fitness for humans, helping to stabilize our bodies, mutations that tightened the core of the SARS-CoV-2 spike protein in new variants may have increased the virus’s fitness. New research led by Penn State reveals that the stem region of the spike protein became progressively tighter over time, and the team thinks this likely improved the virus’s ability to transmit through nasal droplets and infect host cells once in the body. The team said the stem region of the protein that emerged in the most recent Omicron variants is as rigid as it can get, which could ...

Status epilepticus: New inflammatory markers to improve patient care

A rare and nevertheless formidable event in the landscape of epilepsies, New-Onset Refractory Status Epilepticus (NORSE) is a form of prolonged seizure in which the neurons of the epileptic focus endure a continuous discharge of neurotransmitters. It is a medical emergency requiring intensive care management. Indeed, it can cause significant long-term neurological sequelae and is associated with an average mortality rate of 12% in children and 16 to 27% in adults. NORSE can occur in response to an infection or tumor development. However, its origin remains unknown in half of the affected patients despite extensive clinical and biological ...

Making rare cell types visible: Researchers are developing a new method

The human body contains more than 30 trillion cells. Until recently, the sheer number of cells in the organism meant that approaches to understanding human diseases and developmental processes based on the analysis of single cells were a futuristic vision. The development of new sequencing methods is currently revolutionising our understanding of cellular heterogeneity. These technologies can detect rare or even new cell types by extracting and sequencing the genetic information from the cells based on ribonucleic acid chains. In cooperation ...

More than 1,200 LOINC® registrants represent 78 countries for version 2.74 webinar

INDIANAPOLIS -- LOINC®, an international data standard maintained at Regenstrief Institute, hosted an educational release webinar for version 2.74. More than 1,200 participants signed up, representing 78 countries. The hour and a half webinar served as an opportunity for the LOINC team to introduce and explain the new concepts from the 2.74 release update. Participants were presented with opportunities to learn more about each new concept and ask questions. LOINC, short for Logical Observation Identifiers Names and Codes, is a global standard for health terminology. Created and maintained at Regenstrief, LOINC enables the identification, exchange and collection of data across ...

NRG Oncology combined trial long-term results indicate that pathologic complete response is prognostic of outcomes for soft tissue sarcoma patients

Combined long-term survival results from nonrandomized phase II trial NRG Oncology RTOG 0630 and the ancillary analysis of the combined NRG-RTOG 0630/9514 trials indicate that pathologic complete response (pCR) is associated with improved survival outcomes for patients with localized soft tissue sarcoma (STS) who receive preoperative chemoradiotherapy or radiotherapy. This data suggests that pCR can be used as a prognostic factor for clinical outcomes in future STS research. These results were recently published in the JAMA Oncology. NRG-RTOG 0630 and 9514 both evaluated STS patients who were receiving either preoperative image-guided radiotherapy (IGRT; 0630) or neoadjuvant ...

Pensoft joins Advisory Panel to further develop the Journal Comparison Service by cOAlition S

Back in December, we announced that Pensoft joined 27 other publishers in sharing prices and services via the Journal Comparison Service developed by cOAlition S, in order to boost transparency in scholarly publishing. Now, we are up to another challenge: we have joined the Advisory Panel appointed by cOAlition S to help further the improvement and development of this important service. The Advisory Panel consists of twelve members (six publishers and six end-users) representing different stakeholders in the scholarly communication ecosystem. Journal Comparison Service (JSC) is an initiative by cOAlition S aimed to improve ...

Scallop eyes as inspiration for new microscope objectives

Scallop eyes as inspiration for new microscope objectives
Some species of mussels can see. Scallops, for example, have up to 200 eyes that help them detect predators such as an approaching starfish. However, the eyes of scallops differ significantly from the human eye. While in our eyes the combination of cornea and lens creates an image on the retina, in scallop eyes light is focused by a hemispherical mirror. Optical imaging with lenses or mirrors Creating images with mirrors instead of lenses is especially common in astronomical telescopes, in order to capture as much light as possible from planets, stars and galaxies. In the Schmidt telescope developed in the 1930s by Bernhard Schmidt (1879-1935) and still in use in many observatories today, ...


Quantum computing will radically alter the application of copyright law, study says

Ochsner Health & Wellness Day in New Orleans East set for March 9

Protecting joints from bacteria with mussels

Researchers investigate immune response of a man who received 217 Covid vaccinations

Proceed with caution – the meteoric rise of zero-alcohol drinks

USC collaborates with startup supporter Techstars to encourage intellectual property development

Who military service members see as credible to discuss secure firearm storage for suicide prevention

Low birthweight coupled with overweight in 20s linked with ‘massive risk’ of early type 2 diabetes in men

DNA aptamer drug sensors can instantly detect cocaine, heroin and fentanyl – even when combined with other drugs

New project will use next-gen at-home rapid test to track COVID-19, RSV, and flu

SRI relaunches the PARC Forum event series as it celebrates the first anniversary of acquiring the storied Palo Alto Research Center

An inside look at Beech tree disease

New AI model draws treasure maps to diagnose disease

Breastfeeding after COVID-19 booster can give babies antibodies

Researchers closing in on genetic treatments for hereditary lung disease, vision loss

COVID-19 associated with increased risk for autoimmune inflammatory rheumatic diseases up to a year after infection

UC Irvine receives $15 million NSF grant for integrative movement research

University of Houston engineer Metin Akay featured in study highlighting 50 scientists' contributions to biomedical engineering advancements

JWST captures the end of planet formation

Good news—MS drugs taken while breastfeeding may not affect child development

Programs intended to reduce health insurance premiums may make coverage less affordable for the middle class

PrEP discontinuation in a US national cohort of sexual and gender minority populations, 2017–22

USC Study: Medicare Part D plans increased restrictions on drug coverage

Sacituzumab govitecan plus platinum-based chemotherapy in breast, bladder, and lung carcinomas

Global study unveils "problematic" use of porn

Newly discovered protein prevents DNA triplication

Less ice in the arctic ocean has complex effects on marine ecosystems and ocean productivity

Antarctica’s coasts are becoming less icy

New research shows migrating animals learn by experience

Modeling the origins of life: New evidence for an “RNA World”

[] Mathematical model provides bolt of understanding for lightning-produced X-rays