Experimental+procedure+for+the+Measurement+of+Isotopes+using+Cerenkov+Radiation

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__**Part 1 - The Volume Effect**__


 * 1) An aqueous solution of 32 P solution has been provided. Place 1 cm 3 of this solution in a polythene 20 ml scintillation vial and count in the scintillation counter in the 3 H channel, which should be set so that the full tritium range is displayed in channel one and a third of the tritium range in channel two (protocol 28)
 * 2) Set up a further 14 scintillation vials with 1 cm 3 of 32 P soln. Add 1 cm 3 of H 2 O to one vial, 2 cm 3 to the next, 3 cm 3 to the next, and so on until 14 cm 3 has been added to the final vial
 * 3) Count them all on the scintillation counter using protocol 28
 * 4) Plot a graph showing the counting efficiency as a percentage of the maximum activity
 * 5) Deduce the optimum counting volume.

__**Part 2 - Colour Quenching**__


 * 1) Put 1 cm 3 of the 32 P solution into a scintillation vial and make up to 12 cm 3 with distilled water
 * 2) Count the sample using protocol 28
 * 3) Add successively 0.1, 0.1, 0.2, 0.4, 0.4, 0.6 and 0.6 cm 3 of the 0.25% v/v of methyl violet in alcohol solution provided to the vial of 32 P
 * 4) Record the counts for after each addition in the both of the channels
 * 5) Work out the channel ratio and plot a graph showing the activity of the solution as a percentage of the unquenched sample against the channel’ ratio
 * 6) Repeat the expt using the 0.25% v/v of methyl orange in alcohol solution provided
 * 7) The quench curves should be identical until a very high degree of quenching is obtained, after which some variation in the two curves may be obtained