Detail Project and Funding

Abstract: This project aims at integrating the major European infrastructures in the field of high-resolution solar physics. The following actions will be taken:
(i) realise Trans-national Access to external European users;
(ii) enhance and spread data acquisition and processing expertise to the Europe-wide community; (iii) increase the impact of high-resolution data by offering science-ready data and facilitating their retrieval and usage;
(iv) encouragecombination of space and ground-based data by providing unified access to pertinent data repositories;
(v) foster synergies between different research communities by organising meetings where each presents state-of-the-art methodologies;
(vi) train a new generation of solar researchers through setting up schools and an ambitious mobility programme;
(vii) develop prototypes for new-generation post-focus instruments;
(viii) study local and non-local atmospheric turbulence, their impact on image quality, and ways to negate their effects;
(ix) improve the performance of existing telescopes;
(x) improve designs of future large European ground-and space-based solar telescopes;
(xi) lay foundations for combined use of facilities around the world and in space;
(xi) reinforce partnership with industry to promote technology transfer through existing networks; (xii) dissemination activities towards society.
The project involves all pertinent European research institutions, infrastructures, and data repositories. Together, these represent first-class facilities. The additional participation by private companies and non-European research institutions maximizes the impact on the world-wide scale. In particular, the project achievements will be of principal importance in defining the exploitation of the future 4-meter European Solar Telescope.

The WP “Large-diameter Etalon Development” (UToV lead, INAF, CNR-INO, AIP) consists in the optimization of the plate design and the mechanical mount for the production of large diameter FPIs with diameter from 100 to 300mm for operation in different gravity orientations. The main goal is to build a 150mm FPI engineering prototype to be tested by interferometer to demonstrate the feasibility of the proposed design. Initial studies for mechanical mounts have been done by the institutes involved in this analysis, limited to Ø150mm FPIs operating in vertical position. This sWP plans to extend the analysis up to Ø300mm for operation in horizontal orientation. Such analysis of FPI designs is a fundamental step in developing future instruments for large solar telescopes such as EST, although the results will also be of undoubted interest for presently operating telescopes.
This WP includes the following tasks:
(I) FEA thermo-mechanical optimization of mechanical mount for FPIs from Ø100mm to Ø300mm for vertical and horizontal operation.
(II) Detailed design of a 150mm FPI prototype in collaboration with IC Optical Systems.
(III) Manufacturing of a FPI prototype composed of two polished plates Ø150mm without coating, the piezoelectric stacks and capacitor pillars needed to adjust the plate parallelism and spacing and the mechanical mount.
(IV) Interferometer tests in a temperature controlled environment at the Optical Measurements and Testing Laboratory of the National Institute of Optics (CNR-INO) in Florence. The FPI cavity will be measured with a 6” beam laser interferometer, controlling the parallelism and spacing of the test plates. Measurements will be performed for different rotation angles in order to discriminate the inherent and gravity induced surface error.
(V) Analysis of the prototype measurements comparing the results with results from FEA analysis.
(VI) Evaluate the possibility to apply reflective coating to the plates to measure the deformations produced by coating stresses.
(VII) Evaluate the possibility to convert the FPI testing prototype into an operational FPI with an electronically and thermally controlled housing for application in a future instrument.