Configurable Slit Unit (CSU)

The most striking feature in the EMIR mechanical design is the choice of a fully cryogenic robotic system which can be remotely reconfigured to form the multislit pattern in the instrument focal plane, the Configurable Slit Unit (CSU), developed by JANSSEN Precision Electronics. This subsystem has obvious functional and operational advantages with respect to the more classical approach of interchangeable multislit masks.

 


 

The CSU is attached onto the front plane of the cold bench. It consists of the following elements:

 

 

Each bar has 4 sensors (capacitors) and using a lookup table calibrated we are able to get its position using an reconstruction algorithm, independently of its orientation and temperature.