Mechanical and electrical tests on the attachment keys for the divertor vertical target

The European divertor outboard channel provides the use of adjustable keys for the attachment system of the ITER divertor components, in particular vertical target and wing. Mechanical and electrical tests will be used to characterise the vertical attachment system. Mechanical tests are aimed to the verification of reaction moment due to friction in different conditions, air or vacuum, while electrical tests will be performed feeding the joint with a DC or AC current. The mechanical test results show that the sliding of the keys occurs correspondingly to an applied torque about 10 times less than the one originated by the halo current and dead weight loads. This implies that the vertical target cannot be held by the friction only but one dumbell key must be fixed. The electrical tests show no damage occurs up to the reference conditions, in spite of a reduction of the unscrewing torque. In the final analysis it can be stated that the dumbell keys are capable to carry safely the expected halo current fraction.