Measurement of the radiation field in CDF

The radiation field in the tracking volume has been measured both with dosimeters and using the silicon current. The two measurements agree within a few percent and show that in the present detector the dose rate agrees with predictions based on run-I data, with a slightly less steep dependence on distance from the beam. For the innermost SVX layer the average fluence rate is 1.3×1010 cm−2 pb−1. Variations of the fluence with the polar angle have been measured, as an effect of 3.1 mm displacement of the beam with respect to the detector axis.