October 1, 2019
A proposed system may detect the hypothesized darkish matter particle in a mass regime not probed by different gadgets.
A. Millar/Stockholm College
Searches for axion particles, one candidate for darkish matter, generally use an instrument known as a haloscope, which converts axions into photons by way of a number of completely different mechanisms. Nevertheless, present devices can sense axions provided that their mass, which is unknown, is not more than a number of tens of 𝜇eV. Alexander Millar, of Stockholm College, and colleagues have proposed a brand new haloscope design, based mostly on axion interactions with plasma, that ought to be capable to prolong the higher detectable axion mass by an order of magnitude.
Current idea predicts that an axion positioned in a magnetic subject will combine with a plasma to create an oscillating present. For sure plasmas, the interplay additionally produces a probably detectable plasmon, a sort of quasiparticle manufactured from oscillating electrons. Utilizing analytical and numerical fashions, the crew confirmed that to provide this plasmon, the plasma’s attribute frequency—the speed at which prices naturally oscillate when displaced by small distances—should match the axion’s frequency, which is dependent upon the particle’s mass.
To supply such a plasma, the crew proposes a cylindrical instrument, 60 cm throughout, containing an array of parallel skinny wires in an exterior magnetic subject. On this association, the wires behave like a plasma whose attribute frequency might be tuned by altering the spacing between the wires. Such a system must be delicate to axions with lots of between 35 and 400 𝜇eV. Whereas the general dimension of current haloscopes determines the axion mass vary they’ll detect, the detection vary of this new instrument relies upon solely on the interwire spacing. This dependency would permit researchers to make an instrument with a bigger quantity, thus rising the chance of detecting an axion.
This analysis was printed in Bodily Evaluate Letters.
Sophia Chen is a contract science author based mostly in Tucson, Arizona.