To calculate the radiation dose in millisieverts (mSv) from a given exposure to a specific type of radiation, we need to know the conversion factor specific to that type of radiation. The conversion factor is determined based on the type of radiation and its energy level.
However, in the information you provided, the term "66kV" refers to the voltage, which is not directly related to the radiation dose. Additionally, "42mgY" is not a recognized unit for radiation measurement.
To accurately determine the radiation dose in millisieverts, we would need information about the type of radiation, such as X-rays, gamma rays, or neutrons, as well as the energy level and duration of exposure.