Wednesday, November 20, 2013

Muon Detection


An image of the shadow of the Moon in muons as produced by the 700m subterranean Soudan 2 detector in the Soudan Mine in Minnesota. The shadow is the result of approximately 120 muons missing from a total of 33 million detected in Soudan 2 over its 10 years of operation. The cross denotes the actual location of the Moon. The shadow of the Moon is slightly offset from this location because cosmic rays are electrically charged particles and were slightly deflected by the Earth's magnetic field on their journey to the upper atmosphere. The shadow is produced due to the shielding effect the Moon has on galactic and cosmic rays, which stream in from all directions. The cosmic rays normally strike atoms high in the upper atmosphere, producing showers of muons and other short lived particles.

Just an update here while looking at Sean Carroll's blog post article, entitled," Scientists Confirm Existence of Moon." While we understand the need for confirmation of the existence of things, seeing how our perception is used in order to make such a statement,  is a statement of such a measure then as to what is real.

 We report on the observation of a significant deficit of cosmic rays from the direction of the Moon with the IceCube detector. The study of this "Moon shadow" is used to characterize the angular resolution and absolute pointing capabilities of the detector. The detection is based on data taken in two periods before the completion of the detector: between April 2008 and May 2009, when IceCube operated in a partial configuration with 40 detector strings deployed in the South Pole ice, and between May 2009 and May 2010 when the detector operated with 59 strings. Using two independent analysis methods, the Moon shadow has been observed to high significance (> 6 sigma) in both detector configurations. The observed location of the shadow center is within 0.2 degrees of its expected position when geomagnetic deflection effects are taken into account. This measurement validates the directional reconstruction capabilities of IceCube. See: Observation of the cosmic-ray shadow of the Moon with IceCube,

So I have spent some time here looking at how this measure is used in term sof such clarifications and this to me is an exciting off shoot of what particle research has done for us. The skies the limit then as to our use of such a measure then is seen and understood in the post written by Sean Carroll.