Members of the LZ team in the LZ water tank after the outer detector setup. Credit: Matthew Kapust, Sanford Underground Research Facility
Berkeley Lab Researchers Record Successful Startup of LUX-ZEPLIN Dark Matter Detector at Sanford Underground Research Facility
A distinctively sensitive and ingenious dark matter detector– the LUX-ZEPLIN (LZ) experiment– has actually passed a check-out stage of startup operations and delivered very first results. LZ is located deep below the Black Hills of South Dakota in the Sanford Underground Research Facility (SURF) and is led by the DOEs Lawrence Berkeley National Laboratory (Berkeley Lab).
The take-home message from this effective start-up: “Were ready and whatevers looking excellent,” said Berkeley Lab senior physicist and previous LZ spokesperson Kevin Lesko. “Its a complicated detector with lots of parts to it and they are all functioning well within expectations,” he stated.
In a paper posted on July 7 on the experiments website, LZ researchers report that with the initial run, LZ is currently the worlds most delicate dark matter detector. LZ representative Hugh Lippincott of the University of California Santa Barbara stated, “We prepare to gather about 20 times more data in the coming years, so were only getting begun. He said with travel seriously restricted, just a few LZ scientists could make the trip to help on website. LZ is supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics and the National Energy Research Scientific Computing Center, a DOE Office of Science user center. The LZ collaboration acknowledges the support of the Sanford Underground Research Facility.
In a paper posted on July 7 on the experiments website, LZ researchers report that with the initial run, LZ is already the worlds most delicate dark matter detector. LZ spokesperson Hugh Lippincott of the University of California Santa Barbara stated, “We plan to gather about 20 times more data in the coming years, so were just getting started.
Searching for into the LZ Outer Detector, utilized to veto radioactivity that can simulate a dark matter signal. Credit: Matthew Kapust/Sanford Underground Research Facility
The countdown might have started already with results from LZs very first 60 “live days” of testing. This period was long enough to confirm that all aspects of the detector were working correctly.
Although it is hidden, due to the fact that it does not discharge, soak up, or scatter light, dark matters existence and gravitational pull are nonetheless fundamental to our understanding of the universe. For instance, the existence of dark matter, which is approximated to be about 85 percent of the total mass of the universe, shapes the type and movement of galaxies, and it is conjured up by scientists to explain what is understood about the large-scale structure and expansion of deep space.
Two embedded titanium tanks filled with ten tonnes of very pure liquid xenon and seen by 2 ranges of photomultiplier tubes (PMTs) able to detect faint sources of light form the heart of the LZ dark matter detector. The titanium tanks reside in a bigger detector system to catch particles that may simulate a dark matter signal.
A schematic of the LZ detector. Credit: LZ partnership
” Im thrilled to see this complex detector all set to attend to the enduring issue of what dark matter is made from,” stated Berkeley Lab Physics Division Director Nathalie Palanque-Delabrouille. “The LZ team now has in hand the most ambitious instrument to do so!”
The manufacturing, style, and installation phases of the LUX-ZEPLIN detector were led by Berkeley Lab task director Gil Gilchriese in conjunction with an international team of 250 scientists and engineers from over 35 organizations in the United States, UK, Portugal, and South Korea. The LZ operations supervisor is Berkeley Labs Simon Fiorucci. Together, the collaboration is hoping to utilize the instrument to tape the very first direct evidence of dark matter, the so-called missing mass of the universes.
Henrique Araújo, from Imperial College London, leads the UK groups and previously the last phase of the UK-based ZEPLIN-III program. He worked very carefully with the Berkeley group and other colleagues to incorporate the international contributions. “We started out with 2 groups with various outlooks and wound up with a highly tuned orchestra working effortlessly together to deliver an excellent experiment,” Araújo said.
An underground detector
Stashed about a mile underground at SURF in Lead, South Dakota, LUX-ZEPLIN is created to catch dark matter in the form of weakly interacting huge particles (WIMPs). The experiment is underground to safeguard it from cosmic radiation at the surface that might drown out dark matter signals.
Particle collisions in the xenon produce visible scintillation or flashes of light, which are recorded by the PMTs, discussed Aaron Manalaysay from Berkeley Lab who, as physics planner, led the collaborations efforts to produce these very first physics results. “The cooperation worked well together to adjust and to understand the detector action,” Manalaysay stated. “Considering we just turned it on a few months back and throughout COVID limitations, it is impressive we have such considerable outcomes currently.”
When a WIMP– a theoretical dark matter particle– collides with a xenon atom, the xenon atom releases a flash of light (gold) and electrons. The flash of light is spotted at the top and bottom of the liquid xenon chamber. An electric field pushes the electrons to the top of the chamber, where they produce a second flash of light (red). LZ will be searching for a particular series of flashes that can not be because of anything aside from WIMPs. Credit: LZ/SLAC
The crashes will likewise knock electrons off xenon atoms, sending them to wander to the top of the chamber under an applied electric field where they produce another flash permitting spatial occasion reconstruction. The attributes of the scintillation help figure out the types of particles communicating in the xenon.
The South Dakota Science and Technology Authority, which handles SURF through a cooperative arrangement with the U.S. Department of Energy, protected 80 percent of the xenon in LZ. Financing came from the South Dakota Governors workplace, the South Dakota Community Foundation, the South Dakota State University Foundation, and the University of South Dakota Foundation.
Mike Headley, executive director of SURF Lab, stated, “The entire SURF team congratulates the LZ Collaboration in reaching this major turning point. The LZ team has actually been a fantastic partner and were proud to host them at SURF.”
Chemists at Brookhaven Lab used this personalized vacuum distillation system to purify direct alkyl benzene required to produce liquid scintillator for the LZ dark matter experiment. Credit: Brookhaven Lab
Fiorucci stated the onsite team deserves unique praise at this startup milestone, considered that the detector was transported underground late in 2019, simply before the beginning of the COVID-19 pandemic. He stated with travel severely restricted, just a few LZ researchers might make the journey to assist on site. The group in South Dakota took outstanding care of LZ.
” I d like to second the appreciation for the team at SURF and would also like to reveal thankfulness to the big number of people who supplied remote assistance throughout the construction, commissioning and operations of LZ, a number of whom worked full-time from their home institutions ensuring the experiment would be a success and continue to do so now,” said Tomasz Biesiadzinski of SLAC, the LZ detector operations supervisor.
” Lots of subsystems started to come together as we started taking data for detector commissioning, calibrations and science running. Turning on a new experiment is tough, but we have an excellent LZ team that worked closely together to get us through the early phases of understanding our detector,” stated David Woodward from Pennsylvania State University who collaborates the detector run planning.
The LZ main detector in the tidy space at Sanford Underground Research Facility after assembly, prior to starting its journey underground. Credit: Matthew Kapust, Sanford Underground Research Facility
Maria Elena Monzani of SLAC, the Deputy Operations Manager for Computing and Software, stated “We had fantastic scientists and software designers throughout the cooperation, who relentlessly supported data movement, data processing, and simulations, permitting for a flawless commissioning of the detector.
With verification that LZ and its systems are operating successfully, Lesko stated, it is time for full-scale observations to begin in hopes that a dark matter particle will clash with a xenon atom in the LZ detector soon.
LZ is supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics and the National Energy Research Scientific Computing Center, a DOE Office of Science user facility. The LZ collaboration acknowledges the help of the Sanford Underground Research Facility.