I am writing a lab report and have hit a snag. My issue is that when I try to calculate the theoretical displacement values i get nonreal answers. I am using helmholtz coils to create the magnetic field, with the magnetic field simply measured using lab instruments. 5.8theoreticalvalues.xls

labreport5.8.doc

I've tried to attach my report so far and the excel sheet i used to calculate the theoretical values, which don't nearly match. Oh, and the b averages should be multiplied by 1000, i was just tinkering to see if my units were incorrect or something. The issue i've run into is that the radius is smaller than the length of the cathode ray tube, so the answer involves taking the root of a negative.... oops. any help would be appreciated. I believe the magnetic field is in gauss.
thanks