"The stored mechanical energy, if you think of it as a spring, shows up as a very high voltage," Besson said. Unlike lighters with a flint mechanism, piezoelectric lighters work when compressed mechanically and suddenly released. The advantage of Antarctica is that it's so radio quiet, this is possible-here in Lawrence, Kansas, it would be challenging with so much radio noise." When we turned it on in the first mission three years ago, ANITA immediately registered signals from Hi-Cal 500 miles away. "It's a very clever idea a couple of graduate students showed could work. "The heart of the Hi-Cal project is a $10 barbeque lighter," Besson said.
While the lead ANITA balloon is laden with thousands of dollars of high-tech gadgetry, the follow-on Hi-Cal balloon uses a piezoelectric lighter anyone could buy at a hardware store as its pinging device. By looking at the ratio of the two signals you can infer the surface properties of Antarctic snow." "That radio-frequency ping, which has a duration of 10 to 20 nanoseconds, is detected by ANITA coming directly from the Hi-Cal transmitter as well as from surface reflection from Antarctica. "Hi-Cal is a companion experiment that flies anywhere from 125 to 620 miles behind the main payload and sends out a ping," Besson said. The Hi-Cal soars above Antarctica to circle the South Pole trailing ANITA. Here is where the Hi-Cal experiment operated by KU comes in to play. "To understand the properties from the radio frequencies ANITA collects, you have to understand the surface reflectivity," Besson said.
"The ANITA experiment is to detect ultra-high energy cosmic rays, and these are detected by virtue of the radio frequency radiation produced when a cosmic ray hits a terrestrial molecule-that creates spray of debris including particles and radio frequency radiation," said David Besson, professor of physics & astronomy at KU, who is leading the Hi-Cal team.īesson said the down-coming cosmic rays generate radio frequencies detected by ANITA primarily as surface reflections, bouncing back up from the surface of Antarctica. To understand the purpose of Hi-Cal, first grasping the research mission of ANITA is key. The Hi-Cal (High-Altitude Calibration) experiment loops around the South Pole, trailing hundreds of miles behind yet another cluster of instruments strapped to a much larger balloon, called ANITA (for Antarctic Impulsive Transient Antenna, and funded by NASA since 2003).The ultimate experimental goal is to measure ultra-high energy neutrinos and ultra-high energy cosmic rays that interact in the Antarctic ice, or with the Earth's atmosphere, creating radio waves.
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