PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

A stopwatch for electron flashes

2013-12-09
(Press-News.org) Contact information: Luise Dirscherl
dirscherl@lmu.de
49-892-180-2706
Ludwig-Maximilians-Universität München
A stopwatch for electron flashes Physicists at Ludwig-Maximilians-Universitaet (LMU) in Munich and the Max-Planck-Institute of Quantum Optics measure the duration of energetic electron pulses using laser fields. A stopwatch made of light can determine the duration of extremely brief electron flashes. Teams based in the Laboratory for Attosecond Physics (LAP) at LMU and at the Max Planck Institute of Quantum Optics have, for the first time, succeeded in measuring the lengths of ultrashort bursts of highly energetic electrons using the electric fields of laser light. Such electron pulses, which behave like ultrashort matter waves, provide time-resolved recordings of processes taking place in molecules and atoms, enabling elementary particles to be "filmed" in four dimensions. The new stopwatch for electrons now permits even more precise investigations of the motions of electrons and atoms on nature's smallest scales.

A temporal resolution of 24 frames per second is sufficient for a succession of still images to be perceived as smooth motion by the human eye. Recording the motions of atoms and charges within matter, which occur on attosecond scales, requires the acquisition of images at a trillion times that rate. The use of electron pulses offers a way to capture such ultrafast processes. Bunches of electrons can be kicked out of a metal surface using laser light. Each electron pulse lasts for a few femtoseconds (a femtosecond is 1000 attoseconds; an attosecond is a billionth of a billionth of a second) and can deliver an almost instantaneous shot of processes within atoms.

However, exactly how long such pulses last has been difficult to determine. Now the LAP team has developed a system for the precise measurement of the duration of energetic (25 keV) electron pulses. The researchers direct the electron pulses at a thin foil of aluminum. There, they interact with a laser pulse which impinges on the foil perpendicularly to the electrons. Under the influence of the laser's electric field, the electrons either gain or lose some energy before passing straight through the foil to a detector. Whether electrons pick up or lose energy during the encounter depends on the precise timepoint at which they interact with the rapidly oscillating electromagnetic laser field. From the energy spectrum at the electron detector, the scientists can deduce the duration of the original electron pulse prior to its interaction with the laser field.

In contrast to the photons that make up laser light, electrons can penetrate deep into the inner constituents of matter. Hence, they not only measure the chronological sequence of events, but also probe the spatial dispositions of the atoms during a reaction. The investigation of matter with extremely brief electron pulses is called "ultrafast electron diffraction". With this technique, one can determine the positions and movements of atoms and charges in both space and time ‒ i.e. in four dimensions. It is now possible to produce electron pulses that last for several hundreds of femtoseconds but, in principle, even attosecond electron flashes can be generated for electron diffraction. And when they eventually become available, these still shorter electron bunches can also be measured with the new technique. With the new stopwatch made of light, that novel regime no longer seems so far away.

### END


ELSE PRESS RELEASES FROM THIS DATE:

Study finds rivers and streams release more greenhouse gas than all lakes

2013-12-09
Study finds rivers and streams release more greenhouse gas than all lakes Rivers and streams release carbon dioxide at a rate five times greater than the world's lakes and reservoirs combined, contrary to common belief. Research from the University of Waterloo ...

Hard rock life

2013-12-09
Hard rock life Scientists are digging deep into the Earth's surface collecting census data on the microbial denizens of the hardened rocks. What they're finding is that, even miles deep and halfway across the globe, many of these communities are somehow ...

NASA's IRIS provides unprecedented images of sun

2013-12-09
NASA's IRIS provides unprecedented images of sun The region located between the surface of the sun and its atmosphere has been revealed as a more violent place than previously understood, according to images and data from NASA's newest solar observatory, ...

Math models enhance current therapies for coronary heart disease

2013-12-09
Math models enhance current therapies for coronary heart disease Equations help explain key parameters of stents that combat artherosclerosis Coronary heart disease accounts for 18% of deaths in the United States every year. The ...

Survey of supposed deep-sea chemical munitions dump off Southern California

2013-12-09
Survey of supposed deep-sea chemical munitions dump off Southern California Preliminary survey reveals trash and 55-gallon drums, but no chemical weapons SAN FRANCISCO, CA — Since World War II, US nautical charts have shown seven "chemical munitions ...

System 90L no longer suspect for development

2013-12-09
System 90L no longer suspect for development The low pressure area known as "System 90L" in the Eastern Atlantic Ocean is no longer suspect for tropical or subtropical development. On Sunday, December 8, System 90L's showers had diminished. The low was non-tropical ...

Mapping the demise of the dinosaurs

2013-12-09
Mapping the demise of the dinosaurs SAN FRANCISCO, CA — About 65 million years ago, an asteroid or comet crashed into a shallow sea near what is now the Yucatán Peninsula of Mexico. The resulting firestorm and global dust cloud caused the ...

Genetic flaw in males triggers onset of liver cancer, diabetes

2013-12-09
Genetic flaw in males triggers onset of liver cancer, diabetes Michigan State University researchers have uncovered a genetic deficiency in males that can trigger the development of one of the most common types of liver cancer and forms of diabetes. The ...

Biomarker linked to aggressive breast cancers, poor outcomes in African-Americans

2013-12-09
Biomarker linked to aggressive breast cancers, poor outcomes in African-Americans ATLANTA — Among African-American women with breast cancer, increased levels of the protein HSET were associated with worse breast cancer outcomes, according to ...

Diabetes identified as risk factor for liver cancer across ethnic groups

2013-12-09
Diabetes identified as risk factor for liver cancer across ethnic groups ATLANTA — Diabetes was associated with an increased risk for developing a type of liver cancer called hepatocellular carcinoma, and this association was highest for Latinos, ...

LAST 30 PRESS RELEASES:

Menopause drug reduces hot flashes by more than 70%, international clinical trial finds

FGF21 muscle hormone associated with slow ALS progression and extended survival

Hitting the right note: The healing power of music therapy in the cardiac ICU

Cardiovascular disease risk rises in Mexico, despite improved cholesterol control

Flexible optical touch sensor simultaneously pinpoints pressure strength and location

Achalasia diagnosis simplified to AI plus X-ray

PolyU scholars pioneer smart and sustainable personal cooling technologies to address global extreme heat

NIH grant aims for childhood vaccine against HIV

Menstrual cycle and long COVID: A relation confirmed

WMO report on global water resources: 2024 was characterized by both extreme drought and intense rainfall

New findings explain how a mutation in a cancer-related gen causes pulmonary fibrosis

Thermal trigger

SNU materials science and engineering team identifies reconstruction mechanism of copper alloy catalysts for CO₂ conversion

New book challenges misconceptions about evolution and our place in the tree of life

Decoding a decade of grouper grunts unlocks spawning secrets, shifts

Smart robots revolutionize structural health monitoring

Serum-derived hsa_circ_101555 as a diagnostic biomarker in non-hepatocellular carcinoma chronic liver disease

Korea University study identifies age 70 as cutoff for chemotherapy benefit in colorectal cancer

Study explores brain cell communication called ‘crosstalk’

4 beer and wine discoveries

Massage Therapy Foundation awards $299,465 research grant to Children’s Hospital of Philadelphia

Chung-Ang University develops chloride-resistant Ru nanocatalysts for sustainable hydrogen production from seawater

Afghanistan’s August 2025 earthquake reveals the cost of international isolation, UN scientists warn

Shortlist announced for Panmure House Prize

Small nuclear RNA base editing a safer alternative to CRISPR, UC San Diego researchers find

Can Hayabusa2 touchdown? New study reveals space mission’s target asteroid is tinier and faster than thought

Millisecond windows of time may be key to how we hear, study finds

Graz University of Technology opens up new avenues in lung cancer research with digital cell twin

Exoplanets are not water worlds

Study shows increasing ‘healthy competition’ between menu options nudges patients towards greener, lower-fat hospital food choices

[Press-News.org] A stopwatch for electron flashes