Dr. Ioana-Theodora Nistea Profile

Dr. Ioana-Theodora Nistea

at Diamond Light Source Ltd

SPIE Involvement:

Author

Publications (10)

Proceedings Article | 4 October 2023 Presentation + Paper

Understanding the role of additive manufacturing in the development of astronomical hardware

Carolyn Atkins, Younes Chahid, James Wells, Marcell Westsik, Katherine Morris, Ciarán Breen, Alastair Macleod, Lawrence Bissell, William Cochrane, Richard Kotlewski, Scott McPhee, Robert Snell, Iain Todd, Mat Beardsley, Michael Harris, Misael Pimentel, Scott McKegney, Jonathan Orr, Simon Alcock, Ioana Theodora Nistea, Simone Cottarelli, Samuel Tammas-Williams

Proceedings Volume 12677, 126770L (2023) https://doi.org/10.1117/12.2677452

KEYWORDS: Design and modelling, Lightweight mirrors, Porosity, Astronomy, Aluminum, Single point diamond turning, Prototyping, Optics manufacturing, Additive manufacturing, 3D printing, Optomechanical components, Astronomical instrumentation engineering, Aluminum mirrors

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Proceedings Article | 4 October 2023 Presentation + Paper

From design to evaluation of an additively manufactured, lightweight, deployable mirror for Earth observation

Marcell Westsik, James Wells, Younes Chahid, Katherine Morris, Maria Milanova, Mat Beardsley, Michael Harris, Lucas Ward, Simon Alcock, Ioana-Theodora Nistea, Simone Cottarelli, Samuel Tammas-Williams, Carolyn Atkins

Proceedings Volume 12677, 1267704 (2023) https://doi.org/10.1117/12.2677303

KEYWORDS: Prototyping, Design and modelling, Single point diamond turning, Optical surfaces, Porosity, Simulations, Mirrors, Mirror surfaces, 3D printing, Additive manufacturing

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Proceedings Article | 3 October 2023 Open Access

Diamond-VeNOM: a high-speed slope profiler for characterizing x-ray mirrors

Ioana-Theodora Nistea, Simon Alcock, Murilo Bazan da Silva, K. Sawhney

Proceedings Volume 12695, 126950A (2023) https://doi.org/10.1117/12.2688134

KEYWORDS: Autocollimators, Metrology, Profilometers, X-ray optics

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Proceedings Article | 16 September 2019 Presentation + Paper

Additively manufactured mirrors for CubeSats

Carolyn Atkins, William Brzozowski, Naomi Dobson, Maria Milanova, Stephen Todd, David Pearson, Cyril Bourgenot, David Brooks, Robert Snell, Wenjuan Sun, Peter Cooper, Simon Alcock, Ioana-Theodora Nistea

Proceedings Volume 11116, 1111616 (2019) https://doi.org/10.1117/12.2528119

KEYWORDS: Mirrors, Additive manufacturing, 3D printing, Prototyping, Metals, Space mirrors, Design for manufacturability, Manufacturing, Aluminum, Nickel

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Proceedings Article | 9 September 2019 Open Access

The Optical Metrology Laboratory at Diamond: pushing the limits of nano-metrology

Ioana-Theodora Nistea, Simon Alcock, Murilo Bazan da Silva, Kawal Sawhney

Proceedings Volume 11109, 1110906 (2019) https://doi.org/10.1117/12.2529401

KEYWORDS: Mirrors, Metrology, X-ray optics, Optical metrology, Diffraction gratings, Synchrotrons, Fizeau interferometers

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Proceedings Article | 9 September 2019 Open Access

Controlling an active bimorph deformable mirror with sub-nanometre resolution

Ioana-Theodora Nistea, Simon Alcock, Vivek Badami, Riccardo Signorato, Kawal Sawhney

Proceedings Volume 11109, 111090E (2019) https://doi.org/10.1117/12.2529322

KEYWORDS: Mirrors, Sensors, Metrology, Deformable mirrors, Power supplies, X-ray optics, Interferometry

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Proceedings Article | 9 September 2019 Presentation + Paper

Lightweighting design optimisation for additively manufactured mirrors

Proceedings Volume 11116, 1111617 (2019) https://doi.org/10.1117/12.2528105

KEYWORDS: Mirrors, Additive manufacturing, Design for manufacturability, 3D printing, Lightweight mirrors, Printing, Polishing, Finite element methods, Surface finishing

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Proceedings Article | 9 September 2019 Paper

First commissioning results of the KB mirrors at the SCS instrument of the European XFEL

G. Mercurio, C. Broers, R. Carley, J. T. Delitz, N. Gerasimova, L. Le Guyarder, L. Mercadier, A. Reich, J. Schlappa, M. Teichmann, A. Yaroslavtsev, M. Cascella, K. Setoodehnia, M. Schneider, B. Pfau, S. Eisebitt, V. Vozda, V. Hájková, L. Vyšín, T. Burian, J. Chalupský, L. Juha, S. G. Alcock, I. Nistea, D. La Civita, H. Sinn, M. Vannoni, A. Scherz

Proceedings Volume 11109, 111090F (2019) https://doi.org/10.1117/12.2530725

KEYWORDS: Mirrors, X-rays, Free electron lasers, Sensors, Computer programming, Diffraction gratings, Scattering, Spectroscopes, Metrology

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Proceedings Article | 10 July 2018 Presentation + Paper

Topological design of lightweight additively manufactured mirrors for space

Carolyn Atkins, Charlotte Feldman, David Brooks, Stephen Watson, William Cochrane, Melanie Roulet, Emmanuel Hugot, Mat Beardsley, Michael Harris, Christopher Spindloe, Simon Alcock, Ioana-Theodora Nistea, Christian Morawe, François Perrin

Proceedings Volume 10706, 107060I (2018) https://doi.org/10.1117/12.2313353

KEYWORDS: Mirrors, Polishing, Surface roughness, Additive manufacturing, Finite element methods, Space mirrors, Aluminum, Single point diamond turning, Lightweight mirrors, Error analysis, 3D printing

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Additive manufacturing (AM), more commonly known as 3D printing, is a commercially established technology for rapid prototyping and fabrication of bespoke intricate parts. To date, research quality mirror prototypes are being trialled using additive manufacturing, where a high quality reflective surface is created in a post-processing step. One advantage of additive manufacturing for mirror fabrication is the ease to lightweight the structure: the design is no longer confined by traditional machining (mill, drill and lathe) and optimised/innovative structures can be used. The end applications of lightweight AM mirrors are broad; the motivation behind this research is low mass mirrors for space-based astronomical or Earth Observation imaging. An example of a potential application could be within nano-satellites, where volume and mass limits are critical. The research presented in this paper highlights the early stage experimental development in AM mirrors and the future innovative designs which could be applied using AM.

The surface roughness on a diamond-turned AM aluminium (AlSi₁₀Mg) mirror is presented which demonstrates the ability to achieve an average roughness of ~3.6nm root mean square (RMS) measured over a 3 x 3 grid. A Fourier transform of the roughness data is shown which deconvolves the roughness into contributions from the diamond-turning tooling and the AM build layers. In addition, two nickel phosphorus (NiP) coated AlSi₁₀Mg AM mirrors are compared in terms of surface form error; one mirror has a generic sandwich lightweight design at 44% the mass of a solid equivalent, prior to coating and the second mirror was lightweighted further using the finite element analysis tool topology optimisation. The surface form error indicates an improvement in peak-to-valley (PV) from 323nm to 204nm and in RMS from 83nm to 31nm for the generic and optimised lightweighting respectively while demonstrating a weight reduction between the samples of 18%. The paper concludes with a discussion of the breadth of AM design that could be applied to mirror lightweighting in the future, in particular, topology optimisation, tessellating polyhedrons and Voronoi cells are presented.

Proceedings Article | 8 September 2016 Open Access

X-ray beam expansion by the application of re-entrant surface profiles to deformable bimorph mirrors

John Sutter, Simon Alcock, Yogesh Kashyap, Ioana Nistea, Hongchang Wang, Kawal Sawhney

Proceedings Volume 9965, 99650E (2016) https://doi.org/10.1117/12.2239116

KEYWORDS: Mirrors, X-rays, Deformable mirrors, Surface finishing, Polishing, Surface finishing, Deformable mirrors, Electrodes, Diamond, Light sources, Speckle, Beam shaping

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