1. IFTSUV: an Imaging Fourier Transform Spectrometer in the UV Anne Millard, 3 rd year PhD student, directed by P. Lemaire and J.-C. Vial

2. FSCSI 18-19 novembre 2004 Scientific objectives Add spectral information to 2D images  Spectra of large structures / structures simultaneously on different positions on the Solar disk Detection of explosive events and fast moving phenomenons Speed distribution: horizontal (imaging) and vertical (spectroscopy) Resolve small structures

3. FSCSI 18-19 novembre 2004 Instrument specifications Wavelength: H-Lyman  (121.6 nm) Spectral resolution:  =0.02nm Depending on the mission: Orbit: heliosynchronous preferred (high TM rates) FOV and spatial resolution: Telescope 3 cm : Field: 0  1.1R  33' x 33', r = 1" high resolution Telescope 30 cm : Field: 30" x 30", r = 0.1" very high resolution

4. FSCSI 18-19 novembre 2004 Working principle Intensity due to spectral component dk Total intensity in the interference pattern Spectral distribution of intensity k=1/  = OPD

5. FSCSI 18-19 novembre 2004 Simulations

6. FSCSI 18-19 novembre 2004 IFTSUV mock-up Folded Michelson, compact and symetric. =200nm Scanning mirror on a nanopositioning translation stage. Beam splitted by central diffraction grating. Beams recombined at the focus of an off axis parabola.

7. FSCSI 18-19 novembre 2004 IFTSUV mock-up parameters Paramètres : = 200 nm R = 4000  = 0.05 nm  = 0.08cm -1  = 25nm Mirror step : 110nm Maximum OPD : ~800  m Measurement points : ~3700 Sources : Visible : red laser 633 nm frequency stabilised and green laser 543.5 nm UV : continuum (white light) + rays (hollow cathode lamp) Detection : Visible : CCD (COHU 4710), 699 x 576 pixels (9.2  m x 8.3  m) UV : EMCCD (ANDOR tech DV 887), 512 x 512 pixels (16  m x 16  m), back illuminated, MgF 2 window

8. FSCSI 18-19 novembre 2004 IFTSUV mock-up Possibility to control the positionning in visible light while working in UV.

9. FSCSI 18-19 novembre 2004 First result

10. FSCSI 18-19 novembre 2004 Difficulties Measurement of the OPD. Maintaining the superpositions of the images at the focus on the whole scanning range. Air flow and variation of environment parameters. Synchronous management of all the electric systems involved in the instrument (detection, control, command)

11. FSCSI 18-19 novembre 2004 Next steps Search of the position OPD = 0 using a combinaison of 2 lasers Set-up of the UV path ( sources and detector)

12. Thank you