Project 8: The world’s most precise neutrino “balance” fits into a normal laboratory

Measuring the fantastically tiny mass of neutrinos is currently the subject of a number of research projects. One of these is Project 8, a collaboration of physicists from eleven American and German research institutions. On the German side, Gutenberg University Mainz and the Karlsruhe Institute of Technology are participating. Financial support for the project is provided primarily by the U.S. Department of Energy, the U.S. National Science Foundation and the PRISMA+ Cluster of Excellence at the University of Mainz.

The goal of Project 8 is to build the world’s most precise experimental setup for measuring neutrino mass. If everything goes as planned, the team will determine the neutrino mass with an accuracy of about 40 meV. By comparison, the sister experiment KATRIN in Karlsruhe is aiming for 200 meV.

The neutrino mass – explosive for the Standard Model

In the Standard Model, neutrinos are considered massless. Since the discovery of neutrino oscillations, however, it is clear that this cannot be true: Neutrinos come in three “flavors,” each with sharply defined mass, which can transform into each other. It is already clear that the neutrino mass can be at most one millionth of the mass of an electron, the next lightest particle in the particle zoo. However, exact values are still unknown – and due to the practically non-existent interaction with matter of the neutrinos, which are therefore often apostrophized as ghost particles, they are notoriously complicated to measure.

Neutrinos apparently do not reach their mass via the usual way of interaction with Higgs bosons, but by another, still mysterious mechanism. Knowing more about the neutrino’s own mechanism of mass generation could decisively extend, if not blow up, the Standard Model. The precise value of the neutrino mass – or actually the masses of electron, muon and tau neutrinos – is something like the key to understanding, since with its help the numerous theories on the subject could be put to the test.

See also  Under the South Pole, scientists are looking for ‘ghost' particles from space

Here’s how Project 8 aims to determine neutrino mass

The team has chosen one of the more straightforward ways to “weigh” the ghost particles, which equates the mass in question with the missing energy of the electron emitted during the beta decay of tritium.

Tritium is a naturally occurring hydrogen isotope found in trace amounts that decays to stable helium with the emission of an electron and a neutrino. The electron and neutrino share the energy released when a neutron is converted into a proton. Project 8 now wants to measure the energy of the released electron. What is then missing from the energy difference between the neutron and the proton must be in the neutrino – and is directly linked to its mass via Einstein’s famous formula.

CRES – a new method for measuring electron energy

To measure electron energy, Project 8 has developed a completely new technique, Cyclotron Radiation Emission Spectroscopy (CRES). In this technique, electrons emitted during tritium decay are passed through a magnetic field that forces them into a spiral motion by the Lorentz force, the frequency of which depends on their kinetic energy. Accelerated electrons emit tiny amounts of so-called cyclotron radiation, whose maximum energy lies at the frequency of the electron’s spiral motion. CRES now measures the spectrum of the cyclotron radiation, uses it to determine the frequency of the electron motion – and ultimately the electron energy.

Compared to the dimensions of other experiments around neutrinos – think of the gigantic tank of KATRIN – the Project-8 setup looks modest: The CRES spectrometer fits comfortably in a normal-sized laboratory.

See also  Were high-energy neutrinos discovered 34 years ago from a supernova?

The Project 8 schedule

Since 2014, the Project 8 team has demonstrated that the CRES technique works in principle and has made initial measurements of the tritium spectrum. Current work includes the production and stabilization of atomic tritium (normally tritium is a dimer), whose narrower energy spectrum should increase the accuracy of the measurement. The final phase of the project is expected to begin in late 2022 and should produce results by 2026.

Meanwhile, the Berlin-based Neutrino Energy Group is already working with an alliance of international scientists on practical applications of neutrinos.

Berlin-based Neutrino Energy Group has recently developed a new type of nanotechnology that can convert the motions of the universe’s most ethereal particles into useful electrical engineering. The Neutrino Energy Group is on the verge of turning “neutrinovoltaics” into reality with the help of doped graphene and an inexhaustible research mind.

The cutting edge of nanotechnology is doped nanographene

In 2016, scientists developed trilayer graphene, a material consisting of three ultrathin layers of doped graphene stacked on top of each other. The researchers discovered that trilayer graphene is capable of increasing kinetic energy to nearly unimaginable levels. They had no idea, however, that Holger Thorsten Schubart, a German energy researcher and founder of the Neutrino Energy Group, had developed a nearly similar substance about a year earlier.

Neutrino photovoltaic technology converts the kinetic energy of neutrinos into electricity

In a patent filed in 2015, Schubart described a technique using doped graphene that converts the kinetic energy of passing neutrinos into electricity. Schubart was inspired by the 2015 discovery that neutrinos have mass to develop a system that could convert the mass of these ethereal particles into useful energy.

See also  Astronomers set traps in Greenland's ice to capture deep-space neutrinos

Although neutrinos are almost undetectable and cannot be stopped by almost any substance, they do have mass, and anything that has mass also contains energy. After developing his own doped graphene nanomaterials long before the rest of the scientific establishment caught up, Holger Thorsten Schubart quickly assembled the Neutrino Energy Group and charged this unprecedented consortium of leading energy scientists and engineers with developing the world’s first neutrino energy devices.

Leave a Reply