Not many Israelis make it all the way to the South Pole. (In fact, very few people go there, at all. Not only is it really, really cold, it is extremely difficult and expensive to transport people, gear and necessities to this remote and inhospitable corner of the earth.) So when we learned that Dr. Hagar Landsman, who recently joined the Weizmann Institute’s Physics Faculty, has a part-time gig at the IceCube neutrino detector array, we simply had to write about her. Landsman’s specialty is particle detectors, and IceCube has 5,000 of them buried under several kilometers of ice. In her brief but intense trips during the Antarctic summer, she and her team retest and recalibrate the detectors one more time before sending them down the borehole. Those detectors are expected to keep functioning for years: Once they are frozen in place, there can be no digging them up for repairs.
You can read about Landsman’s IceCube adventures on our website. At the Institute, she is also working on another set of detectors; these ones will be placed underground in Italy’s San Grasso National Lab in the new and improved XENON project. In parallel, she is working on the successor to IceCube, called ARA, which will be a giant (but relatively shallow) array of radio detectors meant to cast a wide net to catch the highest energy cosmic neutrinos.
Interestingly enough, both IceCube and the current XENON experiment reported “negative results” this past year. XENON is looking for WIMPS – particles that could provide evidence of dark matter. Some similar experiments claimed to have found signs of these particles while others reported no findings, so the controversy about their existence has only been fanned. If they are real, hopefully one or two will react with the ton of liquid Xenon in the new facility. As for the recent IceCube report, which was based on two years of operation, the Institute’s Prof. Eli Waxman, who, together with the late Prof. John Bahcall proposed a model for high-energy neutrinos, is not in the least put out. These particles are nearly massless and they almost never interact with normal matter. (Hence the cubic kilometer detector array, which records these interactions, should find just a tiny fraction of the neutrinos passing through the planet.) Therefore, he says, five to ten years of data will need to be analyzed before any conclusions can be drawn.