- ADC prisms for SPIROU and SPIP- - Technical specifications

Transcription

1 DATE : 19/12/2017 PAGE : 1/ 13 - ADC prisms for SPIROU and SPIP- - Technical specifications Name: L.PARES Institute: IRAP Date: 19/12/2017 Prepared by Accepted by Name: S. BARATCHART, M. LACOMBE Institute: OMP Date: 19/12/2017 Approved and Application authorized by Signature Signature Signature Name: D. KOUACH Institute: OMP Date: 19/12/2017 Summary: This document gives the technical specifications for the Atmospheric dispersion prisms for SPIROU and SPIP Keywords: Cassegrain optics, manufacturing data, ADC DISTRIBUTION LIST

2 DATE : 19/12/2017 PAGE : 2/ 13 DOCUMENT CHANGE RECORD Issue Revision Date Modified pages Reason for change / Observations /10/2017 Creation /12/2017 SPIP ADC included /12/2017 Option

3 DATE : 19/12/2017 PAGE : 3/ 13 Table of Contents 1. INTRODUCTION SCOPE OF THE DOCUMENT APPLICABLE DOCUMENTS REFERENCE DOCUMENTS ACRONYMS INSTRUMENTAL POLARIZATION DELIVERABLES PRODUCTS IDENTIFICATION CONTRACTOR DELIVERABLE PRODUCTS ANTIREFLECTION COATING PERFORMANCES REQUIREMENTS OPTICAL GLUE REQUIREMENTS ATMOSPHERIC DISPERSION CORRECTOR FOR SPIROU (DP1) ATMOSPHERIC DISPERSION CORRECTOR FOR SPIP (DP2)... 11

4 DATE : 19/12/2017 PAGE : 4/ 13 List of Tables Table 1: Contractor Deliverable Products... 6 Table 2: Material data for S-NPH2 and S-FTM Table 3: SPIROU S-NPH2 wedge element manufacturing data... 9 Table 4: SPIROU S-FTM16 wedge element manufacturing data... 9 Table 5: Assembly specifications for SPIROU ADC Table 6: Material data for S-NPH2 and S-FTM Table 7: SPIP S-NPH2 wedge element manufacturing data Table 8: SPIP S-FTM16 wedge element manufacturing data Table 9: Assembly specifications for SPIP ADC... 13

5 DATE : 19/12/2017 PAGE : 5/ INTRODUCTION 1.1. Scope of the document SPIRou is a near-infrared spectropolarimeter / high-precision velocimeter being designed as a new instrument for Canada France Hawaii Telescope. It has two main science goals, the detection and characterization of habitable exo-earths orbiting low-mass stars on the one hand, and the measurement of magnetic fields in young protostars as a proxy to investigate the impact of magnetic fields on star / planet formation on the other hand. This document contains the specifications for the Atmospheric Dispersion Corrector (ADC) prisms Applicable documents N Document Title Document Number Issue / Date 1.3. Reference documents N Document Title Document Number Issue / Date 1.4. Acronyms AD ADC CFHT DP n Qty RD SoW SPE SPE n SPIROU Applicable Document Atmospheric Dispersion Corrector Canada France Hawaii Telescope Deliverable Product number n Quantity Reference Document Statement of Work Specification Specification number n Spectropolarimètre Infrarouge 1.5. Instrumental polarization A particular concern of this type of instrument is the minimization of the instrumental polarization. For the following items, the material selection and their assembly should result in a minimized birefringence level taking into account the effects of gluing, holding stress with thermal changes: Atmospheric dispersion Corrector (ADC)

6 DATE : 19/12/2017 PAGE : 6/ DELIVERABLES PRODUCTS IDENTIFICATION 2.1. Contractor Deliverable Products The ADC assembly for SPIROU /SPIP is composed of two identical null-deviation prisms (ADC1+ADC2). Each ADC1 /ADC2 is composed of two wedged elements of different materials glued together. These two null-deviation prisms are counter-rotated along the optical axis to adjust the total dispersion magnitude and direction to correct the atmospheric dispersion. Table 1: Contractor Deliverable Products N Designation Qty DP 1 SPIROU ADC Assembly1 1 DP 2 SPIP ADC Assembly 1 OPTION DP 3 SPIP ADC Assembly 1 The ADC assemblies for SPIROU and SPIP have different angles for the prisms but use the same glasses and the same antireflection coating Figure 1: SPIROU ADC1 and ADC2 optical layout

7 DATE : 19/12/2017 PAGE : 7/ ANTIREFLECTION COATING PERFORMANCES REQUIREMENTS The antireflection coating used should respect the following requirements: SPE 1 The antireflection coating should have : 2 % max reflection over the wavelength range µm. 1% mean residual reflection over the wavelength range µm. SPE 2 The coating should be optimized for the astronomical bands Y, J, H and K Y (µm) J (µm) H (µm) K (µm) SPE 3 SPE 4 SPE 5 The use of soft coating (not hardened) is not permitted. The antireflection coating should withstand the MIL standards for coatings. The coating should not be sensitive to moisture (from 0 to 100% relative humidity level) 4. OPTICAL GLUE REQUIREMENTS SPE 6 The glue used to bind optical surfaces together should have minimum absorption over the wavelength range µm. SPE 7 The glue should be selected to minimize Fresnel reflection over the wavelength range µm.

8 DATE : 19/12/2017 PAGE : 8/ ATMOSPHERIC DISPERSION CORRECTOR FOR SPIROU (DP1) The ADC assembly for SPIROU is composed of two identical null-deviation prisms SPIROU ADC1 and SPIROU ADC2. Each ADC1 /ADC2 is composed of two wedged element of different materials glued together. These two null-deviation prisms are counter-rotated along the optical axis to adjust the total dispersion magnitude and direction to correct the atmospheric dispersion. SPE 8 SPE 9 SPE 10 SPE 11 SPE 12 The contactor should deliver one assembly of two (2) prisms The Contractor should use the materials listed in Table 2 Each wedged element should respect the specifications given in Table 3 and Table 4 depending on the material The assembly of two wedged prisms to form ADC1 or ADC2 should respect the specifications given in Table 5 Each ADCx prism should have the following minimum transmission which include: Antireflection efficiency (99%), all internal transmissions and Fresnel Reflection. Wavelength (µm) Transmission of one ADCx prism Table 2: Material data for S-NPH2 and S-FTM16 S-NPH2 Data from OHARA Catalog S-FTM16 Data from OHARA Catalog Young Modulus (GPa) Poisson s coefficient CTE Linear thermal expansion coef. (10-6 /K) Refractive index µm µm µm µm

9 DATE : 19/12/2017 PAGE : 9/ 13 Table 3: SPIROU S-NPH2 wedge element manufacturing data S-NPH2 wedge element Quantity 2 (1 for ADC 1 and 1 ADC 2) S-NPH2 from OHARA Material Refractive index nominal from catalog at +/ Abbe constant +/- 1 % Stress birefringence < 2 nm/cm (goal) Bubble and other inclusions Max. 3 bubbles or inclusions of 0.1 mm maximum size. No inclusions Inhomogeneity and striae n < No striae visible Mechanical diameter 60 mm mm Clear aperture 50 mm +/ 1 mm Central thickness 5 +/- 0.1 mm Angle /- 10 arc seconds Surfaces form tolerance Flat: 5 fringes nm on the clear aperture Irregularity: 1 fringe spacing@632.8 nm on the clear aperture Scratch-dig Rms micro roughness 3 nm Lateral face Grounded Antireflection coatings on the outer face (not glued) respecting all the specifications from 3. Table 4: SPIROU S-FTM16 wedge element manufacturing data S-FTM16 wedge element Quantity 2 (1 for ADC 1 and 1 for ADC 2) S-FTM16 Material Refractive index nominal +/ Abbe constant +/- 1 % Stress birefringence < 2 nm/cm (goal) Bubble and other inclusions Max. 3 bubbles or inclusions of 0.1 mm maximum size. No inclusions Inhomogeneity and striae n < No striae visible Mechanical diameter 60 mm mm Clear aperture 50 mm +/ 1 mm Central thickness 5 +/- 0.1 mm Angle /- 10 arc seconds Surfaces form tolerance Flat: 5 fringes nm on the clear aperture Irregularity: 1 fringe spacing@632.8 nm on the clear aperture Scratch-dig Rms micro roughness 3 nm Lateral face grounded Antireflection coatings on the outer face (not glued) respecting all the specifications from 3.

10 DATE : 19/12/2017 PAGE : 10/ 13 Table 5: Assembly specifications for SPIROU ADC Prism ADC1 or ADC2 for SPIROU Quantity Composition Glue angle between wedged element (ϴx, ϴy) Angular error ϴz between wedged elements along the optical axis (z) External diameter of the assembly Induced birefringence due to thermal and hygrometry range [-10, +20] C, 0 to 100% of relative humidity Must survive in the thermal and hygrometry range, [-10, +30] C, 0 to 100% of relative humidity The greatest thickness of S-NPH2 will be indicated on the lateral face of the S- NPH2 prism by a mark. 2 using previous wedged elements 1 S-NPH2 wedged element+ 1 S-FTM16 wedged element < 1 arc minute < 15 arc minutes 60 mm mm Should be less than 2 nm/cm in a 30 mm diameter disk centered on the element.

11 DATE : 19/12/2017 PAGE : 11/ ATMOSPHERIC DISPERSION CORRECTOR FOR SPIP (DP2) (OPTION DP3) The ADC for SPIP is composed of two identical null-deviation prisms SPIP ADC1 and SPIP ADC2. Each ADC1 /ADC2 is composed of two wedged element of different materials glued together. These two null-deviation prisms are counter-rotated along the optical axis to adjust the total dispersion magnitude and direction to correct the atmospheric dispersion. SPE 13 The contactor should deliver one assembly of two (2) prisms. OPTION: one additional assembly of two (2) prisms. SPE 14 The Contractor should use the materials listed in Table 6 for the wedged element SPE 15 Each wedged element should respect the specifications given in Table 7 and Table 8 depending on the material SPE 16 The assembly of two wedged prisms should respect the specifications given in Table 9 SPE 17 Each ADCx prism should have the following minimum transmission which include: Antireflection efficiency (99%), all internal transmissions and Fresnel Reflection. Wavelength (µm) Transmission of one ADCx prism

12 DATE : 19/12/2017 PAGE : 12/ 13 Table 6: Material data for S-NPH2 and S-FTM16 S-NPH2 Data from OHARA Catalog S-FTM16 Data from OHARA Catalog Young Modulus (GPa) Poisson s coefficient CTE Linear thermal expansion coef. (10-6 /K) Refractive index µm µm µm µm Table 7: SPIP S-NPH2 wedge element manufacturing data S-NPH2 wedge element Quantity 2 (1 for SPIP ADC 1 and 1 for SPIP ADC 2) S-NPH2 from OHARA Material Refractive index nominal from catalog at +/ Abbe constant +/- 1 % Stress birefringence < 2 nm/cm (goal) Bubble and other inclusions Max. 3 bubbles or inclusions of 0.1 mm maximum size. No inclusions Inhomogeneity and striae n < No striae visible Mechanical diameter 60 mm mm Clear aperture 50 mm +/ 1 mm Central thickness 5 +/- 0.1 mm Angle /- 10 arc seconds Surfaces form tolerance Flat: 5 fringes nm on the clear aperture Irregularity: 1 fringe spacing@632.8 nm on the clear aperture Scratch-dig Rms micro roughness 3 nm Lateral face Grounded Antireflection coatings on the outer face (not glued) respecting all the specifications from 3.

13 DATE : 19/12/2017 PAGE : 13/ 13 Table 8: SPIP S-FTM16 wedge element manufacturing data S-FTM16 wedge element Quantity 2 (1 for SPIP ADC 1 and 1 for SPIP ADC 2) S-FTM16 Material Refractive index nominal +/ Abbe constant +/- 1 % Stress birefringence < 2 nm/cm Bubble and other inclusions Max. 3 bubbles or inclusions of 0.1 mm maximum size. No inclusions Inhomogeneity and striae n < No striae visible Mechanical diameter 60 mm mm Clear aperture 50 mm +/ 1 mm Central thickness 5 +/- 0.1 mm Angle /- 10 arc seconds Surfaces form tolerance Flat: 5 fringes nm on the clear aperture Irregularity: 1 fringe spacing@632.8 nm on the clear aperture Scratch-dig Rms micro roughness 3 nm Lateral face grounded Antireflection coatings on the outer face (not glued) respecting all the specifications from 3. Table 9: Assembly specifications for SPIP ADC Prism SPIP ADC 1 or 2 Quantity Composition Glue angle between wedged element (ϴx, ϴy) Angular error ϴz between wedged elements along the optical axis (z) External diameter of the assembly Induced birefringence due to thermal and hygrometry range [-10, +20] C, 0 to 100% of relative humidity Must survive in the thermal and hygrometry range, [-10, +30] C, 0 to 100% of relative humidity The greatest thickness of S-NPH2 will be indicated on the lateral face of the S- NPH2 prism by a mark. 2 using previous wedged elements 1 S-NPH2 wedged element+ 1 S-FTM16 wedged element < 1 arc minute < 15 arc minutes 60 mm mm Should be less than 2 nm/cm in a 30 mm diameter disk centered on the element.