World’s first detector designed by dark matter researchers records rare events

A revolutionary detector that aims to use quartz to capture high-frequency gravitational waves was built by researchers at the ARC Center of Excellence for Dark Matter Particle Physics (CDM) and the University of Western Australia.

During its first 153 days of operation, two events were detected that could, in principle, be high-frequency gravitational waves, which had never been recorded by scientists before.

Such high frequency gravitational waves may have been created by a primordial black hole or a cloud of dark matter particles.

The results were published this month in Physical examination letters in an article titled “Rare Events Detected with a Bulk Acoustic Wave High Frequency Gravitational Wave Antenna.” “

Gravitational waves were originally predicted by Albert Einstein, who theorized that the motion of astronomical objects could cause space-time curvature waves to be sent out into the universe, almost like waves caused by stones falling into a flat pond. This prediction was proven in 2015 by the first detection of a gravitational wave signal.

Scientists believe that low-frequency gravitational waves are caused by the rotation and fusion of two black holes or the disappearance of a star in a black hole.

Since then, a new era of gravitational wave research has begun, but the current generation of active detectors exhibit high sensitivity to low frequency signals only; the detection of high frequency gravitational waves has remained an unexplored and extremely difficult front in astronomy. Despite the attention paid to low frequency gravitational waves, there is also a significant number of theoretical proposals for high frequency GW sources, for example primordial black holes.

The new detector designed by CDM’s research team to capture high-frequency gravitational waves is built around a quartz crystal massive acoustic wave (BAW) resonator. At the heart of this device is a quartz crystal disc that can vibrate at high frequencies due to sound waves passing through its thickness. These waves then induce an electrical charge through the device, which can be detected by placing conductive plates on the outer surfaces of the quartz disc.

The BAW device was connected to a superconducting quantum interference device, known as SQUID, which acts as an extremely sensitive amplifier for the low voltage signal of the BAW quartz. This assembly was placed in multiple radiation shields to protect it from stray electromagnetic fields and cooled to low temperature to allow low energy acoustic vibrations of the quartz crystal to be detected as high voltages using the l ‘SQUID amplifier.

The team, which included Dr Maxim Goryachev, Professor Michael Tobar, William Campbell, Ik Siong Heng, Serge Galliou and Professor Eugene Ivanov, will now work to determine the nature of the signal, potentially confirming the detection of gravitational waves at high frequency.

Mr Campbell said that a gravitational wave is only one possible candidate that has been detected, but other explanations for the result could be the presence of charge particles or the build-up of mechanical stresses, a meteoric event or an internal atomic process. It could also be due to a very high mass of dark matter candidates interacting with the detector.

“It’s exciting that this event has shown that the new detector is sensitive and is giving us results, but now we need to figure out exactly what those results mean,” said Campbell.

“With this work, we have demonstrated for the first time that these devices can be used as very sensitive gravitational wave detectors. This experiment is one of only two currently active in the world in search of high gravitational waves. frequency at these frequencies and we have plans to extend our reach to even higher frequencies, where no further experimentation has yet been done. Development of this technology could potentially provide the first detection of gravitational waves to these frequencies. high frequencies, giving us new insight into this area of ​​gravitational wave astronomy.

“The next generation of the experiment will involve building a clone of the detector and a muon detector sensitive to cosmic particles. If two detectors discover the presence of gravitational waves, it will be really exciting,” he said. he declares.