Scanning slit for HIE-ISOLDE: vibrational test (linear motion actuator from UHV design, speed = 2.5 mm/s)

This report summarizes the results of a series of tests performed on the prototype HIE-ISOLDE diagnostic box (HIE-DB) regarding the vibrations and drifts in the transverse position of the scanning blade while moving inside or outside the box. To monitor the transverse position of the blade, a series of 0.1 mm diameter holes were drilled on it and their positions were tracked with an optical system. The linear motion actuator was acquired from UHV design (model LSM38-150-SS), is driven by a stepper motor and has all the guiding mechanisms outside vacuum. The maximum speed of the scanning blade during the tests was 2.5 mm/s. The transverse movement of the slit in the direction perpendicular to the movement was lower than 50 m, and is dominated by the displacement of the contact point of the applied force on the lead-screw. An offset on the slit position was observed while changing the direction of movement of the blade, its amplitude being of the order of 30 m. The amplitudes of the displacements of the transverse position of the scanning slit are within the accepted tolerances of 100 m. The tested mechanism can be adopted as a guiding system for the scanning slits for the HIE-ISOLDE diagnostic boxes in terms of mechanical vibrations for this speed of movement. Further tests at the nominal blade speed of 10 mm/s are recommended.