PIC-based project

i'm working on a project of radiadion visual display.
i need a circuit diagram that can read output from the gamma detector and make it available for input to a microcontroller(PIC16F877/PIC16F887). and how to utilise the PIC timers to count time and then detect gamma detections over time!

i will really appreciate any other way i can use to interface my detector with the microcontroller!

any help!

Can you give some details of the gamma detector you will be using?
Simple basic information like this always helps with a possible answer!!!!!!