A hadron radiation installation adapted to subject a target to irradiation by a hadron radiation beam includes a target support configured to support, preferably immobilize, a target; a hadron radiation apparatus adapted to emit a hadron radiation beam along a beam axis to irradiate the target supported by the target support, the radiation beam penetrating into the target. The radiation apparatus has a control system at least comprising a beam penetration depth control allowing at least to control and vary the penetration depth of the radiation beam into the target. The installation has a radiation beam range sensor device adapted to determine the penetration depth of said radiation beam into the target, where the range sensor device includes a gamma camera responsive to prompt gamma rays that are emitted while the hadron radiation beam penetrates into the target.