Individual contributors have become less and less prominent in scientific fields as the discipline itself has matured. Some people are still in the public spotlight for his discoveries, like Peter Higgs with the Higgs boson, which several other physicists also theorized about the same time he did. However, the actual data that eventually gave Dr. Higgs and François Englert their Nobel prize was collected by the Large Hadron Collider, arguably one of the largest technical projects that took thousands of scientists over decades to design, build, and test. .
Subatomic particles aren’t the only things that need large, complex detectors to study. With the help of an underground research facility in South Dakota, a team at Lawrence Berkeley National Laboratory has developed, implemented, and tested the world’s most sensitive dark matter detection system.
The project, known as LUX-ZEPLIN, or LZ, has a history that would give any project manager nightmares. A team of 250 scientists and engineers from 35 different institutions collaborated on the project, whose main detector was delivered to its underground home in South Dakota just before the COVID pandemic forced many of those participants to remain in their homes. for the next two years.
Despite all the LZ issues, in December 2021, it formally went online and started collecting data. Those data formed the basis of a recent paper, showing that LZ is the most sensitive dark matter detector ever created.
That’s not to say that it actually saw dark matter on its first run. Notoriously difficult to detect using any method other than gravity, dark matter remains an enigma to this day. But scientists have perfected a detection methodology that they believe will help them better understand it, and it is this technology that forms the basis of the LZ system.
Credit: Matthew Kapust
A giant tank filled with liquid xenon comprises most of the system, with an array of photomultiplier tubes (PMTs) that can detect when one of the myriad xenon atoms is hit by a particle that could “mimic a dark matter signal.” In that case, the atom lights up, which is then detected by one of the PMTs, which can also isolate the spatial area and direction the particle was traveling.
If the detector were on the surface, too many of these particles would create too much noise compared to the dark matter signal. Therefore, the detector is located below the Earth’s surface at the Sanford Underground Research Facility (SURF). SURF is also home to other sensitive experiments that benefit from the shielding provided by the Earth’s surface, so LZ fits right in with the rest.
credit – LZ/LZ/SLAC Collaboration
So far, LZ is only a few months old, but even those results are exciting for the team that initially designed and built the detector. However, there is much more science to come, with the current plan to collect 20 times more data than before. Given the difficulty of detecting dark matter and the general bias in science that more data is better, it sounds like an excellent proposition for finding dark matter, if it exists at all. Perhaps the experiment with the Latin word for light in its name is the first to shed some light on the mystery of dark matter.
Learn more:
SURF – Researchers Record Successful Startup of LUX-ZEPLIN Dark Matter Detector at Sanford Underground Research Center
LBNL – The LZ dark matter experiment
UT- New dark matter detector draws a blank in first round of testing
UT- Searching for dark matter inside the Earth
Main Image:
Some of the team members responsible for the LUX-ZEPLIN experiment.
Credit: Matthew Kapust