The design of a breadboard cryogenic optical delay line for DARWIN

Abstract

TNO TPD, in cooperation with Micromega-Dynamics, SRON, Dutch Space and CSL, has designed a compact breadboard cryogenic delay line for use in future space interferometry missions. The work is performed under ESA contract in preparation for the DARWIN mission. The breadboard (BB) delay line is representative of a future flight mechanism, with all materials and processes used being flight representative. The delay line has a single stage voice coil actuator for Optical Path Difference (OPD) control, driving a two-mirror cat's eye. Magnetic bearings provide frictionless and wear free operation with zero-hysteresis. Overall power consumption is below the ESA specification of 2.5 W. The power dissipated on the optical bench at 40 K is considerably less than the maximum allowable 25 mW. The BB delay line will be build in the second half of 2004. The manufacturing and assembly phase is followed by a comprehensive test program, including functional testing at 40 K in 2005. The tests will be carried out by Alcatel Space and SAGEIS-CSO.

The DARWIN breadboard optical delay line verification programme

“…The dynamic delay line consists of four main elements [3]: Two-mirror Cat's Eye Magnetic Bearing (MB) guiding system Voice Coil OPD actuator and amplifier OPD and MB controller and electronics…”

The manufacturing, assembly and acceptance testing of the breadboard cryogenic Optical Delay Line for DARWIN

“…The mirrors are plated with a 200 micron layer of Alumiplate ®, a pure Aluminium that prevents bimetallic effects which can cause differential thermal bending of the mirrors. More information on the design of the delay line is given in [3].…”

The DARWIN breadboard cryogenic optical delay line

“…C. van den Dool (1) , W. Gielesen (1) , F. Kamphues (1) , N. Loix (2) , P.P. Kooijman (3) , C. de Vries (3) , H. van Weers (3) , K. Fleury (4) , Y. Stockman (4) , G. Velsink (5) , J. Benoit (6) , A. Poupinet (7) , F. Sève (7) (1) TNO Science & Industry, Stieltjesweg 1, 2628 CK, Delft, THE NETHERLANDS, Email: teun.vandendool@tno.nl (2) Micromega-Dynamics, Rue des Chasseurs Ardennais, B-4031, Angleur (Liège), BELGIUM, Email: nloix@micromega-dynamics.com (3) SRON, Sorbonnelaan 2, 3584 CA, Utrecht, THE NETHERLANDS, Email: p.p.kooijman@sron.nl (4) CSL, Parc Scientifique du Sart Tilman, Angleur (Liège), BELGIUM, Email: kfleury@ulg.ac.be (5) Dutch Space, Newtonweg 1, 2333 CP, Leiden, THE NETHERLANDS, Email: g.velsink@dutchspace.nl (6) Alcatel Alenia Space, Bld. du Midi, F-06156 Cannes La Bocca, France, Email: jeremie.benoit@alcatelaleniaspace.com (7) SAGEIS-CSO, 70, avenue des Martyrs, 38000 Grenoble, FRANCE, Email: a.poupinet@sageis-cso.fr ABSTRACT TNO, in cooperation with Micromega-Dynamics, SRON, Dutch Space and CSL, has designed a compact breadboard cryogenic delay line (figure 1) for use in future space interferometry missions.…”