March 30, 2014 at 23:44German scientists measured electron mass 13 times more accurate than before
An electron is the first elementary particle known to man. It was discovered in 1897 by the British physicist Joseph John Thompson. Unlike many other particles, which used to seem elementary, and then turned out to be composed of other particles, the electron is still considered one of the fundamental bricks of the universe, and its mass and electric charge are one of the main physical constants. Therefore, an accurate measurement of its mass is of great interest. Recently, a team of German physicists managed to break the record for the accuracy of electron mass measurements.
An electron is a light particle, and measuring its mass directly is very difficult. Scientists used a highly ionized carbon atom in which only one electron remained. Carbon ion was trapped in a penning trap(pictured) - a device for storing charged particles in a uniform magnetic field. By measuring the characteristics of a system consisting of a nucleus of a carbon atom and one electron, scientists were able to very accurately determine the ratio of the mass of an electron to the nucleus of carbon-12. The mass of the carbon nucleus is very well known - it is a kind of standard: the atomic unit of mass, by definition, is equal to one twelfth of the mass of the nucleus of the carbon atom.
The adjusted value of the electron mass is 0.000548579909067 a.m. Usually, an increase in the accuracy of measuring the mass of elementary particles by an order of magnitude is achieved in 10 to 20 years. This time, the accuracy was increased by 13 times just a few years after the previous record-breaking electron mass measurement.
An article describing the experiment was published in the journal Nature.Press release from the Max Planck Institute for Nuclear Physics at the University of Heidelberg (in German).
An electron is a light particle, and measuring its mass directly is very difficult. Scientists used a highly ionized carbon atom in which only one electron remained. Carbon ion was trapped in a penning trap(pictured) - a device for storing charged particles in a uniform magnetic field. By measuring the characteristics of a system consisting of a nucleus of a carbon atom and one electron, scientists were able to very accurately determine the ratio of the mass of an electron to the nucleus of carbon-12. The mass of the carbon nucleus is very well known - it is a kind of standard: the atomic unit of mass, by definition, is equal to one twelfth of the mass of the nucleus of the carbon atom. The adjusted value of the electron mass is 0.000548579909067 a.m. Usually, an increase in the accuracy of measuring the mass of elementary particles by an order of magnitude is achieved in 10 to 20 years. This time, the accuracy was increased by 13 times just a few years after the previous record-breaking electron mass measurement.
An article describing the experiment was published in the journal Nature.Press release from the Max Planck Institute for Nuclear Physics at the University of Heidelberg (in German).