Semiconductor particle detectors can get worn down until they’re useless and dead. ...Or are they? Scientists found a simple trick that can bring them back to life.
Colliders are a familiar concept in physics; smash particles into each other and watch what happens. The things that allow us to watch what happens are the detectors to either side of a particle beam. The detectors are lattices of semiconductors, which are materials that don't conduct well at low temperatures, but get better as they warm. As the particles collide and scatter, they pass through the detectors – creating and sending off electrons, which tell scientists what was going where.
The problem is, having particles pass very quickly through a lattice does quite a bit of damage, which deforms the lattice. Within these crags and deformations, the telltale electrons get temporarily caught. As they (relatively) slowly work their way out, they give off a current, called leakage. It gets stronger and stronger over time as more damage is done to the detector. Eventually, the electrons given off by the particle are obscured by the leakage noise of the trapped electrons, and the detector is useless. Radiation-damaged detectors were routinely taken out of commission, and as particle accelerators got more powerful, and the streams of particles got more intense, the detectors were killed off faster and faster.
And then, a team that worked with cryogenic detectors realized the significance of the semiconductor. As temperature drops, it becomes less of a conductor. When the team got the detectors down to temperatures less than 100 kelvin, they suddenly came back from the dead. The defects in the lattice were still there, but while the electrons created by the particle traveled through the undamaged parts quickly, the electrons that got trapped in the damaged parts of the detectors were so affected by the drop in temperature that their entrapment stopped being temporary. They were well and truly stuck, and so could not give out the slow leakage that ruined the detection of the particles.
Particle physicists, delighted at not having to shell out more money and spend more time repairing damaged detectors, called this the Lazarus Effect. You gotta love it when physics gets biblical.
Top Image: Muriel