Featured Research

from universities, journals, and other organizations

Shaking the electron has strengthened quantum mechanics

Date:
August 23, 2012
Source:
National Center for Nuclear Research (NCBJ)
Summary:
Atomic orbital electrons react to change of nucleus electric charge following each beta decay and to flying nearby particles emitted from the nucleus. Physicists have simulated such processes for 6He nuclei. Theoretical calculations were recently confirmed.

Beta decay.
Credit: Image courtesy of National Center for Nuclear Research (NCBJ)

Atomic orbital electrons react to change of nucleus electric charge following each beta decay and to flying nearby particles emitted from the nucleus. NCBJ physicists have simulated such processes for 6He nuclei. Theoretical calculations were recently confirmed by an experiment performed in the GAEN accelerator centre in Caen (France). That way the sudden approximation calculation method (one of the oldest methods employed to solve quantum mechanics problems) was directly validated.

Decays of atomic nuclei are potential sources of information on fundamental phenomena occurring in the quantum world. Unfortunately it is a rather difficult task to model such processes. Yet NCBJ physicists have successfully simulated the process of neutron→ proton conversion in singly ionized 6He atom nucleus and correctly predicted its impact on the atomic orbital sole electron. Theoretical calculations were recently confirmed by an experiment performed in the GAEN accelerator centre in Caen (France). That way the sudden approximation calculation method (one of the oldest methods employed to solve quantum mechanics problems) was directly validated.

Nucleus of a 6He ion is composed of two protons and four neutrons. In a singly ionized ion the nucleus is orbited by a single electron. Surplus of neutrons makes such nuclei unstable, they undergo the so-called beta-minus decays in which one of the neutrons is transformed into a proton. To preserve electric charge, an electron is emitted from the decaying nucleus. Each emitted electron is accompanied by an electron anti-neutrino. In effect, a stable 6Li nucleus (still orbited by a single electron) is produced.

"During each beta-minus decay the orbiting (atomic) electron is impacted because of two reasons. Firstly, the total electric charge of the nucleus is changing since three protons are suddenly appearing in place of two protons. Secondly, a negatively charged emitted electron is flying nearby. It is plenty of stimulation for the orbiting electron: one might say that it is shaken very strongly. In result it is excited to a higher orbital or completely struck out of the atom" explainsProfessor Zygmunt Patyk from NCBJ.

Quantum mechanics uses wave functions to describe particles. The functions may be used to calculate probabilities that the particle will take some determined states.

"The 6He ion selected for calculations is almost a textbook case: single electron orbiting within a relatively simple potential well of the nucleus" said Dr. Katarzyna Siegień-Iwaniuk from NCBJ.

Electrons emitted by the decaying nuclei move at a speed close to the light velocity. They cross orbital electron clouds in times shorter than one billionth part of a nanosecond (i.e. 10-18 s). In quantum mechanics, problems in which interactions are so short are treated by finding a superposition of some final state wave functions (in our case: single electron within the 6Li ion) that jointly approximate the initial state wave function (in our case: single electron within the 6He ion). That trick is known as the sudden approximation method. It has been applied for many years (almost from the days quantum mechanics was born) but has never been directly verified in any experiment.

Professor Patyk's team has been collaborating with teams of physicists working in GAEN accelerator centre in Caen (Normandie, France) for several years. Calculations performed by NCBJ physicists to the accuracy of 4 significant places yielded the 2.3% probability that beta-decay will be liberating the sole orbital electron of the 6He ion, i.e. will be producing a totally ionized lithium atom. To a comparable accuracy that result was confirmed by some experiments performed at the French accelerator.

"Such a good agreement between theoretical predictions and experimental findings in such a simple (almost textbook) system is the first direct proof that the sudden approximation computational method utilized to solve quantum mechanics problems for almost a century is indeed correct" points out Professor Patyk.

NCBJ physicists have also managed to determine factors responsible for liberating the 6He sole orbital electron. The performed analyses have indicated that the ionization is caused in 99% cases by change of the nucleus total electric charge, and only in 1% cases by the fast electron emitted by the decaying nucleus.

The results co-authored by members of both collaborating teams were recently published in Physical Review Letters. The Polish team work was co-financed by a Polish Ministry for Science and Higher Education grant and by a Polish National Science Centre grant.


Story Source:

The above story is based on materials provided by National Center for Nuclear Research (NCBJ). Note: Materials may be edited for content and length.


Journal Reference:

  1. C. Couratin, Ph. Velten, X. Fléchard, E. Liénard, G. Ban, A. Cassimi, P. Delahaye, D. Durand, D. Hennecart, F. Mauger, A. Méry, O. Naviliat-Cuncic, Z. Patyk, D. Rodríguez, K. Siegień-Iwaniuk, J-C. Thomas. First Measurement of Pure Electron Shakeoff in the β Decay of Trapped 6He+ Ions. Physical Review Letters, 2012; 108 (24) DOI: 10.1103/PhysRevLett.108.243201

Cite This Page:

National Center for Nuclear Research (NCBJ). "Shaking the electron has strengthened quantum mechanics." ScienceDaily. ScienceDaily, 23 August 2012. <www.sciencedaily.com/releases/2012/08/120823090906.htm>.
National Center for Nuclear Research (NCBJ). (2012, August 23). Shaking the electron has strengthened quantum mechanics. ScienceDaily. Retrieved September 30, 2014 from www.sciencedaily.com/releases/2012/08/120823090906.htm
National Center for Nuclear Research (NCBJ). "Shaking the electron has strengthened quantum mechanics." ScienceDaily. www.sciencedaily.com/releases/2012/08/120823090906.htm (accessed September 30, 2014).

Share This



More Matter & Energy News

Tuesday, September 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Argentina's Tax Evaders Detected, Hunted Down by Drones

Argentina's Tax Evaders Detected, Hunted Down by Drones

AFP (Sep. 30, 2014) — Argentina doesn't only have Lionel Messi the footballer, it has now also acquired "Mesi" the drone system which monitors undeclared mansions, swimming pools and soy fields to curb tax evasion in the country. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
Do Video Games Trump Brain Training For Cognitive Boosts?

Do Video Games Trump Brain Training For Cognitive Boosts?

Newsy (Sep. 29, 2014) — More and more studies are showing positive benefits to playing video games, but the jury is still out on brain training programs. Video provided by Newsy
Powered by NewsLook.com
CERN Celebrates 60 Years of Science

CERN Celebrates 60 Years of Science

Reuters - Business Video Online (Sep. 29, 2014) — CERN, the European Organisation for Nuclear Research, celebrates 60 years of bringing nations together through science. As Joanna Partridge reports from inside the famous science centre it's also planning to turn the Large Hadron Collider particle accelerator back on after an upgrade. Video provided by Reuters
Powered by NewsLook.com
This 'Invisibility Cloak' Is Simpler Than Most

This 'Invisibility Cloak' Is Simpler Than Most

Newsy (Sep. 28, 2014) — Researchers from the University of Rochester have created a type of invisibility cloak with simple focal lenses. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins