Determining background radiation in a decay spectrum

[physguy09]

I was working on calibrating some newly purchased software onto our lab computers when I noticed that the decay spectrum on the screen did not look exactly as it does on published material. I attribute this to background radiation effects (correct me if I am wrong please), so I decided the best way to test the background rate would be to run the detector being used without a radioactive source.

My question: how do I then use this data to remove it from generated spectra? I initially thought I would run the detector without the source for the same amount of time as I had with the source, but this would mean running it for days at a time in cases of weaker sources...seams rather impractical. May someone point me in the right direction please?

 

[Bob S]

If you are looking at nuclear gammas (e.g., Cs¹³⁷), the local environment (e.g., shielding) can affect the amplitude of the Compton edge and backscatter peaks.