Space Travel News  
TIME AND SPACE
Doubly-excited electrons reach new energy states
by Staff Writers
Washington DC (SPX) Nov 15, 2018

file illustration only

Positrons are short-lived subatomic particle with the same mass as electrons and a positive charge. They are used in medicine, e.g. in positron emission tomography (PET), a diagnostic imaging method for metabolic disorders. Positrons also exist as negatively charged ions, called positronium ions (Ps-), which are essentially a three-particle system consisting of two electrons bound to a positron.

Now, commercially available lasers are capable of producing photons that carry enough energy to bring the electrons of negatively charge ions, like Ps?, to doubly-excited states, referred to as D-wave resonance. Positronium ions are, however, very difficult to observe because they are unstable and often disappear before physicists get a chance to analyse them.

Sabyasachi Kar from the Harbin Institute of Technology, China, and Yew Kam Ho from the Academia Sinica, Taipei, Taiwan, have now characterised these higher energy levels reached by electrons in resonance in these three-particle systems, which are too complex to be described using simple equations.

This theoretical model, recently published in EPJ D, is intended to offer guidance for experimentalists interested in observing these resonant structures. This model of a three-particle system can be adapted to problems in atomic physics, nuclear physics, and semiconductor quantum dots, as well as antimatter physics and cosmology.

In this study, the authors first test the validity of their theoretical approach by showing that the resonance parameters for negatively charged hydrogen ions (H-) - modelled as a three-particle system made up of two electrons and one proton - are in agreement with previous studies.

The authors then calculate, for the first time, new resonance states associated with the positronium ion (Ps-) in higher energy regions by modelling it as a three-particle system. In turn, they elaborate on seven modes of resonance for the electrons that have never before been reported.

S. Karand Y. K. Ho (2018), Two-photon double-electron D-wave resonant excitation in the positronium negative ion, European Physical Journal D 72: 193, DOI: 10.1140/epjd/e2018-90250-4
Related Links
Springer
Understanding Time and Space


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only


TIME AND SPACE
Half moons and pinch points: Same physics, different energy
Onna, Japan (SPX) Nov 13, 2018
When physicists send neutrons shooting through a frustrated magnet, the particles spray out the other side in signature patterns. The designs appear because, even at low temperatures, atoms in a frustrated metal oscillate in time with each other. One distinctive pattern, known as a "pinch point," resembles a bow-tie and holds wide acclaim in the world of spin liquids. Pinch points are often accompanied by unsung crescent patterns called "half moons," but the physics linking the phenomena has never been ... read more

Comment using your Disqus, Facebook, Google or Twitter login.



Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

TIME AND SPACE
TIME AND SPACE
Colonizing Mars means contaminating Mars

Oxia Planum favoured for ExoMars surface mission

Scientists capture the sound of sunrise on Mars

Atmospheric opacity over Opportunity drops to storm-free levels

TIME AND SPACE
Lunar Outpost unveils lunar resource prospecting rover

European-built Service Module arrives in US for first Orion lunar mission

Roscosmos to Study Possibility to 3D Print Lunar Soil Details for Space Repairs

First moon walk's commemorative plaque sold for $468,500

TIME AND SPACE
Evidence for ancient glaciation on Pluto

SwRI team makes breakthroughs studying Pluto orbiter mission

ALMA maps temperature of Jupiter's icy moon Europa

NASA's Juno Mission Detects Jupiter Wave Trains

TIME AND SPACE
Laser tech could be fashioned into Earth's 'porch light' to attract alien astronomers

Laboratory experiments probe the formation of stars and planets

NASA retires Kepler Space Telescope, passes planet-hunting torch

Rocky and habitable - sizing up a galaxy of planets

TIME AND SPACE
New horizon for space transportation services

Rocket Lab reaches orbit again, deploys more satellites

Fleet Space Technologies' first satellites launched by Rocket Lab

DARPA, Army select companies to develop hypersonic missile propulsion

TIME AND SPACE
China unveils new 'Heavenly Palace' space station as ISS days numbered

China's space programs open up to world

China's commercial aerospace companies flourishing

China launches Centispace-1-s1 satellite

TIME AND SPACE
NASA's OSIRIS-REx executes fourth asteroid approach maneuver

Dawn falls silent as a successful mission comes to an end

Cosmic Detective Work: Why We Care About Space Rocks

Aboard the first spacecraft to the Trojan asteroids









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.