Quote:
Originally Posted by leviterande
Interesting. One question first. does the detector needs to be almost directly above the ore regardless of altitude of airplane or satellite? or can this detector find an ore from a distance or different latitude equally well? I suspect only directly above?
This method is really detecting very very weak signals. But does the signal depend on altitude from the ore or is signal change with altitude negligible?
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Hi leviterande,
The Bickel isotope detector is used to make a survey of a plot of ground from above. It can be used in a satellite, an airplane, a car, or by hand when walking over the ground, and holding the scintillator probe downward. The data map that is generated is about the same regardless of what altitude, but at satellite heights, the resolution is not as good as when measuring from a plane or on the ground, which give the same resolution. The probe consists of a lead tube that is open at one end to expose a scintillator crystal. While the crystal is shielded from light, the open lead end allows gamma and alpha radiation to pass through the light filter. The purpose of the lead tube is to shield gamma from entering at the sides, and only enter through the open end. A photomultiplier behind the crystal converts tiny flashes of light to electrical signals which are analyzed, then sent to a counter to determine how many counts are coming from a gold isotope (or other materials that are being searched for). This device will give meaningful data only when it is pointed downward and used to make a survey of a plot of land. In theory, you may be able to rig it to work for searching an area at an angle different than down, but I have not heard of it being used in that way.
The signals are extremely weak as you say. Dr. Bickel told me it is best to use this detector at times of the day when the solar activity is low. Otherwise the noise from the solar activity interferes with getting reliable readings. He recommended mornings before noon, around 10am for the work he did in the western USA and in Mexico.
Best Wishes,
J_P