**8.1.8.4 Parasite Activation**

One of the most relevant issues in Cyclotron facility is the activation of the materials inside the cyclotron room during daily operation. As cyclotron room is a close and hardly shielded facility all activation products will ever be contained inside its room and the activation levels will only be monitored and measured during providers maintenances, in this opportunity, frotis are taken of the most suitable materials to be activated and they are measure in spectrometer. On the other hand, gaseous activation is continuously monitored with proper devices set inside the chimney. As first defense line, the facility has a 200 m circuit through which gaseous particles travel during 24 hours before getting into the chimney to be release to the atmosphere. As our cyclotron do not have gaseous target all the airborne particles come from the air inside the room, so they are characterized by their extremely short half lives, around nano or micro seconds. Periodcally, frotis are taken from the chimney to be measure in spectrometer.

For any maintenance that need the "backdoor" of the cyclotron to be removed, exposition rate must be below 0.5 mR/h as it is establish in NVC2259. If it is not, maintenance personnel must wait until this level is reached.

Finally, it must be said that in operation conditions Cyclotron is fully shielded allowing a maximum of 10 mSv at 1 m in the axial direction of the magnet, and such a value is only reached one or twice a day in the production time that is less than 2 hours accounting all the running.
