Industry partnership a win-win for Wenzel and researchers
Wenzel brought expertise and equipment, and scientists provided research and a suitable location in new research that aims to help understand the impact of cosmic radiation on equipment used to detect gravitational waves and dark matter.
Researchers from the Dark Matter Centre partnered with Wenzel - a manufacturer of industrial measuring and metrology equipment – in the research above ground in Melbourne and 1km underground in the Stawell Underground Physics Laboratory (SUPL).
The research aimed to determine whether cosmic rays disturb precision quartz oscillators and acoustic resonators.
The team of researchers including Maxim Goryachev, Ben McAllister, William Campbell, Mike Tobar, Eugene Ivanov, Mehran Mossammaparast and Mike Sawicki compared measurements from ultra-low noise Wenzel quartz oscillators above ground in Melbourne and in SUPL.
The team compared the results above ground and underground. Conventional measurements found no compelling difference in the overall amount of oscillator noise between the locations. However, multi-scale entropy, a technique that measures patterns and predictability, showed that the underground signals were more regular and predictable.
Taken together with the two rare events observed an earlier study using a cryogenic detector, the result strengthens the case that cosmic rays affect quartz resonators, although the experiment does not yet provide direct, event-by-event proof.
Researcher Maxim Goryachev says the findings could progress physics research and a range of areas.
“The new analysis could help distinguish genuine signals from cosmic-ray disturbances in precision timing systems and acoustic high-frequency gravitational-wave detectors. It can also guide decisions about shielding, underground operation and the use of particle detectors to reject false events,” he says.
“High-frequency gravitational waves are also connected to the search for dark matter. They could be produced by primordial black-hole mergers, early-Universe processes or structures associated with some dark-matter models. Primordial black holes may themselves make up part of dark matter.
“Quartz detectors may also be able to detect certain dark-matter candidates directly when they deposit energy as vibrations, or phonons, inside the crystal. High-frequency gravitational-wave searches therefore provide both direct and indirect ways of exploring physics beyond our current understanding.”
Dr Goryachev says the partnership between industry and researchers had proved valuable opportunities to both.
“This project combined Wenzel’s expertise in exceptionally stable oscillators, our university research in fundamental physics and noise analysis, and access to a unique underground laboratory. No single organisation could easily provide all these capabilities.
“We are also part of GravNet, a multinational collaborative search for high-frequency gravitational waves, where acoustic resonators will contribute to the search. International detector networks are particularly valuable because a genuine gravitational wave should be observable across multiple locations, while a cosmic-ray strike or other local disturbance should not.”
Future experiments will combine multiple resonators with dedicated muon detectors so that cosmic-ray particles and acoustic events can be recorded simultaneously.
The group also plans longer underground measurements with tighter control of temperature, vibration and electromagnetic interference to test whether cosmic rays caused the events already observed and establish how to limit future high-frequency gravitational wave and dark matter searches.
Read the white paper on the Wenzel website.