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DOE Pulse
  • Number 331  |
  • February 21, 2011

How to build a stronger neutrino detector

LBNE-BNL: Photomultiplier tube

LBNE-BNL:
Photomultiplier tube.

Scientists at DOE’s Brookhaven National Laboratory working on the proposed Long Baseline Neutrino Experiment (LBNE) have set up a death trap for the key components of the project’s future neutrino catchers. Their goal: Find out what makes fragile photomultiplier tubes break, sometimes setting off a shattering chain reaction, and using what they learn to design more resilient detectors.

At a once-defunct Navy facility in Rhode Island, the researchers submerge sample photomultiplier tubes in 500,000 gallons of pressurized water, punch a small hole through their sides, and watch as the glass cracks, crunches, and, just milliseconds later, implodes. High-speed cameras and sensors record the implosion and subsequent shock wave.

The scientists are using what they learn to explore ways to avoid a catastrophic cascade among the thousands of tubes that will eventually line the two massive detectors of LBNE — for example, by making the glass stronger and/or encasing each tube in an enclosure that would deflect or absorb the shock wave.

Once they have a new design in hand, the researchers will return to the Navy tank for more testing. The current LBNE schedule calls for a final design of the photomultiplier tube array by 2014.

[Karen McNulty Walsh, 631.344.8350,
kmcnulty@bnl.gov
]