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Jonker, W.A. (author), Kuiper, S. (author), Nijenhuis, J.R. (author), Dekker, A. (author), Bos, A. (author), van de Ven, E.A. (author), Chun, M. (author), Priem, H. (author), Breukers, M. (author)
An adaptive secondary mirror (ASM) is currently being developed for the UH2.2 telescope, consisting of a slumped 620mm convex aspherical facesheet, manipulated by 210 variable-reluctance actuators and supported on a siliconaluminium alloy support structure. The total power dissipation of the actuators is expected to be under 3 Watts. The ASM...
conference paper 2020
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Tajdari, F. (author), Berkhoff, A.P. (author), Naves, M. (author), Nijenhuis, M. (author), de Boer, A. (author)
article 2020
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Nijenhuis, M. (author)
In the framework on the Netherlands in-service testing program for heavy-duty vehicles of the Ministry of Infrastructure and Water management TNO has conducted three on-road emission tests with PEMS on a N3 Euro VI Step-C truck conform Regulation EU No. 582/2011 [1] as amended by EU No. 2016/1718 [2], to verify that the vehicle meets the...
report 2019
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Witvoet, G. (author), Nijenhuis, J.R. (author), Kramer, L. (author)
The preparations for the design and construction of the Extremely Large Telescope (ELT) are in full swing. One of the most critical components of this enormous telescope is its segmented primary mirror (M1), for which TNO, in collaboration with VDL, has designed the mechanical segment support in the period 2015-2016. The dynamic performance of...
article 2018
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Witvoet, G. (author), Nijenhuis, J.R. (author), Kramer, L. (author)
The preparations for the design and construction of the Extremely Large Telescope (ELT) are in full swing. One of the most critical components of this enormous telescope is its segmented primary mirror (M1), for which Netherlands Organisation for Applied Scientific Research (TNO), in collaboration with VDL, has designed the mechanical segment...
conference paper 2018
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Nijenhuis, J.R. (author), Braam, B.C. (author), Hamelinck, R.F.M.M. (author)
The mirror segments for the E-ELT and TLT are nearly equal in size and shape (hexagonal, 1.2 m over flat sides). They are very thin (about 50 mm) compared to their size. Supporting these mirrors and obtaining high optical performance is a challenge from design and manufacturing point of view. TNO has designed and build (together with VDL-ETG)...
conference paper 2016
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Heijmans, J.A.C. (author), Nijenhuis, J.R. (author), Bos, A. (author)
The E-ELT is the European Extremely Large Telescope with a primary mirror of 39 meters that is being developed by ESO for the European astronomical community and ESO members. For the realisation of the E-ELT, TNO Space and Scientific Instrumentation proposes several technical contributions. These are, among others, the mirror support structure,...
article 2016
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Nijenhuis, J.R. (author), Heijmans, J.A.C. (author), de Breeje, R. (author), Hazelebach, R.L.M. (author), de Vreugd, J. (author), Crowcombe, W.E. (author), Naron, D.J. (author), Fritz, E.C. (author), Borghi, G. (author), Navarro, R. (author), Sillari, L. (author), Sambenedetto, E. (author), Eder, J. (author), Kamphues, F.G. (author)
Described is the M1 segment support, as designed by TNO in the period 2015- 2016. The design has significantly changed and improved compared to the earlier designs. During the period 2009-2010 prototypes for the primary mirror support of the E-ELT have been developed. These have been extensively tested by ESO. Design improvement were found to be...
conference paper 2016
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Witvoet, G. (author), den Breeje, R. (author), Nijenhuis, J.R. (author), Doelman, N.J. (author)
Controller design based on dynamic analysis proves compliant performance of highly accurate actuators for piston-tip-tilt correction of primary mirror segments for the European Extremely Large Telescope.
article 2015
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Witvoet, G. (author), den Breeje, R. (author), Nijenhuis, J.R. (author), Hazelebach, R.L.M. (author), Doelman, N.J. (author)
Segmented primary mirror telescopes require dedicated piston-tip-tilt actuators for optimal optical performance. Netherlands Organisation for Applied Scientific Research (TNO) has developed various prototypes of such actuators, in particular for the E-ELT. This paper presents the dynamics analysis and feedback control results for a specific two...
article 2014
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Witvoet, G. (author), de Breeje, R. (author), Nijenhuis, J.R. (author), Hazelebach, R.L.M. (author), Doelman, N.J. (author)
Segmented primary mirror telescopes require dedicated piston-tip-tilt actuators for optimal optical performance. TNO has developed various prototypes of such actuators, in particular for the E-ELT. In this paper the control results of a specific two-stage prototype will be presented.
conference paper 2014
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Nijenhuis, J.R. (author), Hamelinck, R.F.M.M. (author), Braam, B.C. (author)
The mirror segments for the E-ELT and TLT are nearly equal in size and shape (hexagonal, 1.2 m over flat sides). They are very thin (about 50 mm) compared to their size. Supporting these mirrors and obtaining high optical performance is a challenge from design and manufacturing point of view. TNO has designed and build (together with VDL-ETG)...
conference paper 2012
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de Vreugd, J. (author), te Voert, M.J.A. (author), Nijenhuis, J.R. (author), Pijnenburg, J.A.C.M. (author), Tabak, E. (author)
Adhesives are widely used in optomechanical structures for bonding optical components to their mounts. The main advantage of using adhesives is the excellent strength to weight ratio. Adhesive bonding is seen as a desirable joining technique as it allows for greater flexibility in design. A disadvantage of adhesives however is the limited...
conference paper 2012
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Nijenhuis, J.R. (author), Hamelinck, R.F.M.M. (author)
ESO is preparing to build the E-ELT which will be the largest optical telescope in the world. Its primary mirror will be Ø39.3 m and will consist of nearly 1000 hexagonal segments of 1.2 meter width. Each segment is to be supported by the same structure although the segments vary in size and shape, hence this will cause variable surface...
conference paper 2011
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van den Dool, T.C. (author), Hamelinck, R.F.M.M. (author), Kruizinga, B. (author), Gielesen, W.L.M. (author), Braam, B.C. (author), Nijenhuis, J.R. (author), Loix, N. (author), Luyckx, S. (author), van Loon, D. (author), Kooijman, P.P. (author), Swinyard, B.M. (author), TNO Industrie en Techniek (author)
TNO, together with its partners Micromega and SRON, have designed a cryogenic scanning mechanism for use in the SAFARI Fourier Transform Spectrometer (FTS) on board of the SPICA mission. The optics of the FTS scanning mechanism (FTSM) consists of two back-to-back cat's-eyes. The optics are mounted on a central "back-bone" tube which houses all...
conference paper 2010
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Nijenhuis, J.R. (author), Hamelinck, R.F.M.M. (author), Braam, B.C. (author), Cayrel, M. (author), TNO Industrie en Techniek (author)
The largest optical telescope in the world will be the E-ELT. Its primary mirror will be 42m in diameter. This mirror will consist of 984 hexagonal segments that are all individually supported. Each mirror will be controlled in six DOF while local shaping of the segments is provided by so called warping harnesses. These will correct for focus,...
conference paper 2010
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Braam, B.C. (author), Meijer, E.A. (author), Nijenhuis, J.N. (author), Vink, R.J.P. (author), Kamphues, F.G. (author), TNO Industrie en Techniek (author)
TNO is developing the Basic Angle Monitoring Opto-Mechanical Assembly for the GAIA mission of ESA, a space telescope that will create a map of the universe including distant stars and planets. GAIA is being built by EADS Astrium and scheduled for launch in 2011. Due to its stability and hardness properties, Silicon Carbide has been chosen for...
conference paper 2009
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Meijer, E.A. (author), Nijenhuis, J.N. (author), Vink, R.J.P. (author), Kamphues, F.G. (author), Gielesen, W.L.M. (author), Coatantiec, C. (author), TNO Industrie en Techniek (author)
To measure the relative motions of GAIA's telescopes, the angle between the telescopes is monitored by an all Silicon Carbide Basic Angle Monitoring subsystem (BAM OMA). TNO is developing this metrology system. The stability requirements for this metrology system go into the pico meter and pico radian range. Such accuracies require extreme...
conference paper 2009
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Jongert, M.W.A. (author), van de Broek, J. (author), Nijenhuis, N. (author), Guise, A. (author), van Meeteren, N. (author), TNO Kwaliteit van Leven (author)
B&G, PZ.
report 2009
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Nijenhuis, J. (author), Visser, H. (author), de Man, H. (author), Dekker, B. (author), Mekking, J. (author), Kamphues, F.G. (author), TNO Industrie en Techniek (author)
ESO is building the Phase Referenced Imaging and Microarcsecond Astronomy (PRIMA) facility for the Very Large Telescope Interferometer (VLTI) in Chile. PRIMA will enable interferometric imaging of very faint objects and high precision astrometry with both Unit (UT) and Auxiliary (AT) telescopes. The PRIMA facility consists of four major sub...
conference paper 2008
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