1. The problem statement, all variables and given/known data A collider has an average electron current of 10 milliAmps and an average positron current of 5 milliAmps.If the ring radius is 100 m and there is one electron bunch and one positron bunch with uniform density, radius 1 µ and length 2 mm, what is the average luminosity in cm–2s–1 ? 2. Relevant equations L=N_1 N_2/A * f density = N/(AT) 3. The attempt at a solution Ok so I know the target thickness (T) is 2mm with and Area (A) of pi * (1µ)^2 The density I am having a problem with. I don't know how to incorporate the current given or the ring radius. Just having a hard time with this question in general. Not sure where to start or where to plug everything in. Please help - thanks!