The radiation dose measurement system for the BaBar electromagnetic calorimeter

An array of 116 p-channel radiation sensitive MOSFET transistors (RadFETs) has been operational for the past 6 years at the BaBar experiment at the PEP-II asymmetric B-factory at the Stanford Linear Accelerator Center (SLAC). This system maps the integrated dose absorbed by different regions of the electromagnetic calorimeter (EMC) during the running of the experiment. We report on the design and implementation of the system and finally, the performance of the monitoring system during the last 6 years of BaBar data-taking.