Variable Decay Constants
Posted: Sat Aug 18, 2012 3:53 am
Advance warning system for solar flares hinges on surprising hypotheses
By James Holloway
August 14, 2012
Scientists may have hit upon a new means of predicting solar flares more than a day in advance, which hinges on a hypothesis dating back to 2006 that solar activity affects the rate of decay of radioactive materials on Earth. Study of the phenomenon could lead to a new system which monitors changes in gamma radiation emitted from radioactive materials, and if the underlying hypothesis proves correct, this could lead to solar flare advance warning systems that would assist in the protection of satellites, power systems and astronauts.
In 2006, nuclear engineer Jere Jenkins of Purdue University noticed a change in the decay rate of a radioactive sample 39 hours before a solar flare. Since joined by a Purdue University professor of Physics named Ephraim Fischbach, Jenkins' subsequent research has reinforced the discovery, using two samples of the same isotope, chlorine 36, in two separate experiments in two different labs.
It isn't just solar flares that seem to induce changes in radioactive decay rate. Changes in solar rotation and activity, and the Earth's position on its orbital path around the Sun also appear to have an effect, and it's the latter variable which seems to have been decisive in the research. Between July 2005 and June 2011, continued monitoring has apparently shown consistent annual variation in the decay rate of chlorine 36, peaking in January and February, and ebbing in July and August.
An 11-year solar cycle is set to peak in 2013, and the researchers claim a solar storm as strong as the Carrington Event of 1859 would be devastating to the technology of today.
"There was so much energy from this solar storm that the telegraph wires were seen glowing and the aurora borealis appeared as far south as Cuba," said Fischbach. "Because we now have a sophisticated infrastructure of satellites, power grids and all sort of electronic systems, a storm of this magnitude today would be catastrophic. Having a day and a half warning could be really helpful in averting the worst damage."
Among the proposed protection measures are the temporary shutting down of satellites (the designs of which would need to be adapted to accommodate this feature) and power networks prior to solar flares.
Purdue's proposed detector uses a sample of manganese 54 which is monitored with a gamma-radiation detector as it decays into chromium 54. It's hoped that anomalies in the rate of decay would indicate forthcoming solar flares. A US patent has been filed to protect the idea.
The research has significant implications for science. To date, the rate of radioactive decay is understood to be constant. Further, the researchers hypothesize that it's neutrinos that are affecting the change in the rate of decay: an idea sure to turn heads.
"Since neutrinos have essentially no mass or charge, the idea that they could be interacting with anything is foreign to physics," Jenkins said. "So, we are saying something that doesn't interact with anything is changing something that can't be changed. Either neutrinos are affecting decay rate or perhaps an unknown particle is."
Jenkins hopes to continue the research, verifying the findings using more sensitive equipment. The latest findings were published last week in the report Analysis of gamma radiation from a radon source: Indications of a solar influence in the journal Astroparticle Physics.
By James Holloway
August 14, 2012
Scientists may have hit upon a new means of predicting solar flares more than a day in advance, which hinges on a hypothesis dating back to 2006 that solar activity affects the rate of decay of radioactive materials on Earth. Study of the phenomenon could lead to a new system which monitors changes in gamma radiation emitted from radioactive materials, and if the underlying hypothesis proves correct, this could lead to solar flare advance warning systems that would assist in the protection of satellites, power systems and astronauts.
In 2006, nuclear engineer Jere Jenkins of Purdue University noticed a change in the decay rate of a radioactive sample 39 hours before a solar flare. Since joined by a Purdue University professor of Physics named Ephraim Fischbach, Jenkins' subsequent research has reinforced the discovery, using two samples of the same isotope, chlorine 36, in two separate experiments in two different labs.
It isn't just solar flares that seem to induce changes in radioactive decay rate. Changes in solar rotation and activity, and the Earth's position on its orbital path around the Sun also appear to have an effect, and it's the latter variable which seems to have been decisive in the research. Between July 2005 and June 2011, continued monitoring has apparently shown consistent annual variation in the decay rate of chlorine 36, peaking in January and February, and ebbing in July and August.
An 11-year solar cycle is set to peak in 2013, and the researchers claim a solar storm as strong as the Carrington Event of 1859 would be devastating to the technology of today.
"There was so much energy from this solar storm that the telegraph wires were seen glowing and the aurora borealis appeared as far south as Cuba," said Fischbach. "Because we now have a sophisticated infrastructure of satellites, power grids and all sort of electronic systems, a storm of this magnitude today would be catastrophic. Having a day and a half warning could be really helpful in averting the worst damage."
Among the proposed protection measures are the temporary shutting down of satellites (the designs of which would need to be adapted to accommodate this feature) and power networks prior to solar flares.
Purdue's proposed detector uses a sample of manganese 54 which is monitored with a gamma-radiation detector as it decays into chromium 54. It's hoped that anomalies in the rate of decay would indicate forthcoming solar flares. A US patent has been filed to protect the idea.
The research has significant implications for science. To date, the rate of radioactive decay is understood to be constant. Further, the researchers hypothesize that it's neutrinos that are affecting the change in the rate of decay: an idea sure to turn heads.
"Since neutrinos have essentially no mass or charge, the idea that they could be interacting with anything is foreign to physics," Jenkins said. "So, we are saying something that doesn't interact with anything is changing something that can't be changed. Either neutrinos are affecting decay rate or perhaps an unknown particle is."
Jenkins hopes to continue the research, verifying the findings using more sensitive equipment. The latest findings were published last week in the report Analysis of gamma radiation from a radon source: Indications of a solar influence in the journal Astroparticle Physics.
