Méchanic at the CPPM – 07/10/05 Françoise RIVIERE – Jean-Luc GIMENEZ - Pierre KARST IR Detector - Test cryostat : Machining - Positioning in the Herschel cryostat Demonstrator - Overview (new optical scheme) - Mirror and prism supports design - Steering mirror fixation - Detectors fixation - required information left Module alignment - Design status Some data for the cold test - Viewport - Cooling down duration - New illumination module

Status of the design and the fabrication of the test cryostat DONE All the components have been delivered 3 D design almost achieved (back flange left) Fabrication = machining (75% done) TO BE DONE : - Complete validation of the design = Back flange - Fabrication = machining + welding + vacuum test + polishing +final vacuum test = delivery in November - Roughness requirement

IR detector positioning COLD TEST IR detector positioning The signal cable has to be in front of the feedthrough.

IR detector positioning COLD TEST IR detector positioning Last design : The signal cable is positioned with a angle of 45° with the horizontal axis. In the Herschel cryostat, we should turn the IR detector for keeping the signal cable in front of the feedthrough.

DEMONSTRATOR : Overview Overview in the visible configuration, in respect with the new optical scheme. The baffling and the aperture of the steering mirror have to be designed

DEMONSTRATOR : Overview Visible detector DEMONSTRATOR : Overview Steering mirror Fixation IR detector Common interface for both detector supports

DEMONSTRATOR : Optic supports Optical components : Rectangular mirror, Zerodur, 310x30x20 Cylindrical mirror, Zerodur,  26 to 34x10 Prism, BK7, Mean thickness 10 mm, 26x26 Support components : Frame and positioning parts, Invar. Clamping and screws : TBD Requirement in the range 300 to 100 K : Positioning tolerance ± 0.1 mm ± 3 arcmin

DEMONSTRATOR : Optic supports Cylindrical mirror Elastic clamping Plan contact with 3 points Mirror support Mirror Centering with 2 small machined plans (depends of the real dimensions of the diameter) Angular support

DEMONSTRATOR : Optic supports Angle DEMONSTRATOR : Optic supports Cylindrical mirror

DEMONSTRATOR : Optic supports Cylindrical mirror Springs for the alignment Screws for fixation Stopper The alignment (in translation and tilt) is done with stoppers and shims on the angle support.

DEMONSTRATOR : Optic supports Rectangular mirror Stop Plan contact Orientation Elastic clamping Elastic clamping

DEMONSTRATOR : Optic supports Prism 6 elastic clamps just in front of each pad The positioning is done by 6 small pads on the lower support plate

DEMONSTRATOR : Optic supports Prism Y adjustment Z adjustment The adjustment of the 3 rotation is required : The positioning is done with 3 axis and the adjustment with screws on cantilever. Y Z X X adjustment

DEMONSTRATOR :Steering mirror Preliminary concept STR support Angular support STR support : TA6V Angular support : Invar The contact plan corresponds to the vertex mirror coordinate

DEMONSTRATOR :Visible detector Preliminary concept

DEMONSTRATOR :IR detector Preliminary concept

Real dimensions of the optics (waiting for the delivery) DEMONSTRATOR : Expected information Real dimensions of the optics (waiting for the delivery) Requirement for the aperture in front of the steering mirror All kind of specification around the optics of the slicer module (Zerodur support shape, alignment requirement, …)

MODULE ALIGNMENT : General concept Illumination with a laser adjusted in the theoretical optical axis. At the entrance focal plan, 2 apertures on the same support (X-Y displacement) At the exit focal plan, on the same support, a target (position) and a razor blade (focal). Laser adjustment target Laser beam

MODULE ALIGNMENT : Laser module

MODULE ALIGNMENT : Expected information Definition of the optical target Orientation of the components Document of the alignment procedure

COLD TEST : Some data Viewport of the cryostat : Useful width = 40 mm Cooling down duration (300 to 100 K): (Detector and thermal screen are not taken into account) Herschel = 5 kg of aluminium = 10 kg of Invar for thermal point of view = 5h Weight estimation for the demonstrator = 25 kg = 12.5 hours Illumination module : Requirement of the design of a new illumination module with plane and spherical mirrors