The Mascot servo-manipulator master station with operators in the Remote Handling control room (left) and the slave unit inside the JET torus.

At JET it has been essential to develop a Remote Handling system which can adapt to the changing configurations and conditions of the JET machine. It was not possible to use a pre-programmed or robotic type of maintenance system for JET.
Instead a Remote Handling system is used which makes use of special manipulators to extend the operators own arms into the radioactive environment.

These manipulators provide the operator with a sense of touch and feel and together with the associated Closed Circuit TV system create a sense of being inside the Torus. The net effect is to enable the human operator to do the task even though it is being done within a hostile environment.

The Mascot manipulator is the basic workhorse of the Remote Handling system. It consists of two force reflecting, Master-Slave, servo-manipulators with load a capacity of 20 kilogram and with a force sensitivity of 100 gram per arm. The units are linked by computer, not mechanically, so that the slave unit can be operated at any distance from the master.

The Mascot manipulator is used by the operator to undertake a wide range of tasks including welding, cutting, bolting, handling and inspection . Many of the tasks are performed using special tooling which has also in the majority of cases been designed and developed at JET. The Mascot manipulator is positioned inside the Torus using a 10 metre long articulated boom

We assess who best fits. You can not identify the right individual through a simple interview process. Aspirants have to spent time with us. Last time we had interviewed about 36 guys and ended up with one new applicant. You can’t force yourself to be a manipulator.

Tony Loving, Head of Remote Handling Group at JET

The Mascot gripper with direct tile handling finger adapters