IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => GCE AS & A2 Level => Sciences => Topic started by: winnie101 on March 27, 2011, 07:18:29 pm

Title: source of gamma radiaiton
Post by: winnie101 on March 27, 2011, 07:18:29 pm

why is cobalt-60 which has a half life of 5 years and emits gamma and beta radiation used as a source for gamma radiation as opposed to radium226 of half life 1600 years and emits alpha, beta, and gamma, or bismuth 214 with half life 20 minutes and emits beta and gamma.
Thanks

Title: Re: source of gamma radiaiton
Post by: tmisterr on April 05, 2011, 03:20:44 pm

in what way are you using the radiation? if you are using it in an experiment testing a particular independent variable, then activity of the source is a variable that should be kept constant. If you use cobalt, the decay is so slow that the activity is relatively constant, same with radium. (I'm assuming you know what activity is). If you use bismuth, a half life of 20 minutes is too fast, so the activity will vary greatly during setting up the measurements, when taking reading e.Take Care. and if activity is a variable that should be kept constant then it beats logic to use bismuth.

Title: Re: source of gamma radiaiton
Post by: winnie101 on April 05, 2011, 09:03:53 pm

Thanks