N21 Determining the Half-life of Thoron essays

N21 Determining the Half-life of Thoron essays N21 determining the Half-life of thoron Objective: To determine and investigate the half life of thoron The decay process of radioactive materials can be described by an exponential law. The equation is: Where f is the decay constant for the individual nuclei. N0 is the number of unstable nuclei at time t=0. Every radioactive nucleus has a definite time interval T1/2. That is the half-life. It is the number of unstable nuclei decreasing to half of original number. After the T1/2 , the number of nuclei reduces half and half. In the experiment, a thoron-air mixture is blown into an ionization chamber subject to a saturation voltage. Alpha-decay of the thorium emanation cause ion formation. This produce a current, whose ternporal progression is recorded with TY-recorder or oscilloscope. The current is the measure of the number of decays per time interval, and thus the recorded graph represents a decay curve. The experiment is to find out the half life of thoron. Radon-222 is the radioactive decay product of radium-226, which is found at low concentrations in almost all rock and soil. Thoron is the nickname for the isotope 220Rn of the element Radon. 220Rn has a 55 second half-life, much shorter than 222Rn(3.8 days). It is a noble gas generated by the decay of radium found in rocks and derived materials. It decays via alpha and beta emission through a series of short-lived progeny. It is not as common as radon in the environment. Indoors it is thought to contribute about 10% of the total airborne radiation dose. The thoron air mixture is blown into an ionization chamber. The alpha decay of thoron causes a current and records by a TY-recorder. The major error sources in the experiment is the environmental error. The environment erro ...