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Thursday, April 14, 2011

න්‍යෂ්ඨික විද්‍යාව-Nuclear science



  • න්‍යෂ්ඨිය, පරමාණුවේ ඇති අධික ඝනත්වයෙන් යුත් ප්‍රදේශයයි.එය න්‍යුට්‍රෝන හා ප්‍රෝටෝන වලින් යුක්ත වේ.මෙම න්‍යෂ්ඨිය පිළිබඳ අධ්‍යයනය කිරීම න්‍යෂ්ඨික විද්‍යාව මගින් සිදුකරයි.

  • The nucleus is the very dense region consisting of nucleons (protons and neutrons) at the center of an atom. Almost all of the mass in an atom is made up from the protons and neutrons in the nucleus, with a very small contribution from the orbiting electrons. ...


Monday, March 14, 2011

පරීක්ෂණාත්මක උපකරණ-Instruments


පරීක්ෂණාත්මක අවශ්‍යතා සදහා භාවිතා කරන මූලික උපකරණ හදුනා ගනිමු....
Lets Identify basic instruments used in nuclear science experiments...


ගයිගර් ගණකය-Geiger muller counter




Geiger counters are used to detect ionizing radiation, usually beta particles and gamma rays, but certain models can detect alpha particles. An inert gas-filled tube (usually heliumneon or argon
with halogens added) briefly conducts electricity when a particle or photon of radiation makes the gas conductive. The tube amplifies this conduction by a cascade effect and outputs a current pulse, which is then often displayed by a needle or lamp and/or audible clicks.
Modern instruments can report radioactivity over several orders of magnitude. Some Geiger counters can be used to detect gamma radiation, though sensitivity can be lower for high energy gamma radiation than with certain other types of detectors. The density of gas in the device is usually low, allowing most high energy gamma photons to pass through undetected. Lower energy photons are easier to detect, and are better absorbed by the detector. Examples of this are the X-ray Pancake Geiger Tube.
Good alpha and beta scintillation counters also exist, but Geiger detectors are still favored as general purpose alpha/beta/gamma portable contamination and dose rate instruments, due to their low cost and robustness. A variation of the Geiger tube is used to measure neutrons, where the gas used is boron trifluoride and a plastic moderator is used to slow the neutrons. This creates analpha particle inside the detector and thus neutrons can be counte...