Hi guys this is my first post since ive joined, so be nice! I've been playing around with a short lens spectrometer at uni, using a strontium-90 beta source. It basically consists of a long steel tube with the source housed at one end, and a solid state detector at the other, mid way there is a magnetic coil to generate the lens used to accelerate the beta paricles. There is an overall length from source to detector of 1.5m, and the tube has a radius of just over 10cm. placed dead centre of the tube is a mass of lead or a "lead-pig" as we call it, which absorbs gamma rays. the detector is connected to an amplifier, which is connected to a counter. I'm attempting to collect data to generate a kurie plot. When accelerated, the beta particle's trajectory is bent around the lead pig, and hits the detector, but when there is no magnetic field present, there is no acceleration of the beta particles....... In that case would I be right to assume that they would (generally) suffer a similar fate to the gamma rays, and be absorbed by the lead pig? in experiment, they do not appear to they still seem to curve around the pig, and hit the detector, and register as a count. the amount of counts at ~0 gauss is comparable to counts with the field on. I am quite puzzed as to how explain this occurence. now just to clarify, I ran a few tests with no source, and the system registered zero counts, so i dont believe there is any problems with the system. also the spectrometer makes use of three lead sheets, or baffles, that fillter out lower energy particles from the test. these do not seem to have any bearing on the problem. (however thay have been the root of some other unrelated problems :/).. does anyone have any idea how to explain this path of beta particles? i wouldnt imagine that the ssd id detecting scattered particles, but i could be wrong.... What do you think? any similar findings or stories?