sshade:databases:ghosst:micro_spectro-gonio_radiometer

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sshade:databases:ghosst:micro_spectro-gonio_radiometer [2017/10/11 06:47] – created Bernard Schmittsshade:databases:ghosst:micro_spectro-gonio_radiometer [2017/10/11 08:10] (current) – Bernard Schmitt
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 +==== SHADOWS Micro Spectro-Gonio Radiometer ====
 +----
  
 +=== Laboratory Experiment facility ===
 +
 +**Facility name:** 
 +
 +Micro Spectro-Gonio Radiometer
 +
 +**Location:**
 +Institut de Planétologie et Astrophysique de Grenoble (IPAG)
 + 
 +CNRS - Université Grenoble Alpes 
 +
 +Saint Martin d’Hères, France 
 +
 +**Persons in charge:**
 + 
 +- Scientific : Pierre Beck,  Assistant Professor  & Bernard Schmitt, Research director
 + 
 +- Technical : Olivier Brissaud, Engineer 
 +
 +----
 +
 +**General description**
 +
 +The new micro spectro-gonio radiometer currently under developement will be optimized for the measurement at low temperature of bidirectional reflectance spectra, over the visible and near-IR (at least from 350 to 4800 nm), of dark and very small samples (organics, meteorites…) down to a few mm3 in volume.
 +
 +[[sample holders]]:
 +
 +It will have 2 major sample holder configurations:
 +
 +- //Open sample holders// (various sizes) in //cold chamber// over -20°C ─ +20°C temperature range.
 +
 +- The //SERAC environmental// cell with cryostats, pumps, pressure and temperature controllers, which allows us to introduce gas(es) of known composition and pressure (10-6 mb - 1 bar) over the sample and controlling and measuring the temperature over the -40°C ─ +80°C range. It will have a set of sample holders (small sizes) adapted to this new setup.
 +
 +[[Tools and sub-systems]]:
 +
 +A number of sample preparation tools and experiment sub-systems are available to the facility:
 +
 +- For samples preparation: another cold chamber (down to -20°C), set of sample holders, several specific tools for ice sample preparation,  2 sets of  sieves, grinders, mortars, saw, balances, microscope, owen, ultra-pure water, several pure gasses, wet chemistry materials a, several owens (up to 1200°C) for sample treatments.
 +
 +- For the experiment: a thermodynamic volumetric system with high accuracy pressure gauges (10-6 to 1 bar), a flow meter (1-10 sccm) and pumps. He-Ne laser + detectors, camera for sample monitoring, …
 +
 +----
 +
 +**Technical characteristics:**
 +
 +[[Spectral range]] : 0.35 - 4.5 µm (< 0.35 & > 4.8 µm: lower S/N) (4.2-4.3µm: atm. CO2 limited)
 + 
 +[[Spectral resolution]] : variable
 + 
 +- mini: < 0.1 nm (but S/N limited)
 + 
 +- maxi: 3 nm (<700nm), 7 nm (<1600nm), 12 nm (<3000nm), 26nm (>3000nm) [May change with future new monochromator]
 +
 +[[Bidirectional Reflectance]] 
 +
 +- ''Incidence angle'': 0° to 75° ; resolution: 2° (can be reduced to 1°) ; maximum sampling : 0.1°
 +
 +- ''Emergence angle'': 0° to 80° for dark / fine grained samples ; resolution : ± 2° (may be reduced to < ± 0.5°, but S/N limited) ; max. sampling : 0.1°
 + 
 +- ''Azimuth angle'': 0° to 180° ; resolution : ± 2° (may be reduced to < ± 0.5°, but S/N limited) ; max. sampling : 0.1° 
 +
 +- ''Phase angle'': up to to 155° ; mini : ~ 7° for dark / fine grained samples 
 +
 +- ''Illumination diameter'' (nadir): 7.5 mm 
 +- ''Observation diameter'' (nadir): 20 mm 
 +
 +[[Photometry]]:
 +
 +''Absolute'': [will be determined during calibration and test phase end 2015 - 2016]
 +
 +- 0.35-1.0 µm: expected better than 1% over all configurations (relative to a calibrated Spectralon 0.99 reference panel) 
 +
 +- 1.0-2.5 µm: expected better than 1% over all configurations 
 +
 +- 2.5-4.5 µm : expected better than 2% over all configurations 
 +
 +''Relative'' : 
 +
 +- better than 0.5% (0.35-4.5 µm)
 +
 +
 +[[File:micro-gonio_design-optique.jpg|500px]]
 +
 +''Picture'': sketch of the micro spectro-gonio radiometer under building at IPAG
 +
 + 
 +[[Samples]]
 + 
 +''Types'': cosmo-materials, synthetic and terrestrial carbonaceous materials, minerals 
 +
 +''Texture'': compact (dark) or granular (dark and/or fine grained < 200µm)  
 +
 +''Grain size'': sub-µm to a 200 µm
 +
 +''Size'': 
 +
 +- 32 mm diameter (for full BRDF down to 75° observation)
 +
 +- 8 mm x 32 mm (for principal plane observation down to 75°) 
 +
 +- 8 mm x 16 mm (for principal plane observation down to 60°)
 + 
 +''Thickness'':
 +
 +- 0.1 mm for dark & fine grained samples (< 20 µm)
 +
 +- up to 5 mm for 'gray' & medium grained samples (< 200 µm)
 +
 +- up to 10 mm for bright & medium/fine grained samples (< 100 µm)
 +
 +
 +[[Temperature]]: 
 +
 +- room temperature or heated 
 +
 +- down to -20°C (in cold room) 
 +
 +- down to -40°C (in SERAC environmental cell)
 +
 +
 +[[Experiment control]]:       
 +
 +- PC/Windows,  fully software controlled (LabView©). Automatic acquisition of all spectral/geometric configurations
 + 
 +[[Acquisition time]]: [will be determined during calibration and test phase end 2015 - 2016]
 +
 +- typical: 1 mn for 200 spectral channels in visible (S/N dependent)
 +
 +- total: <1 hour for 100 spectral channels and 100 geometries 
 +
 +[[Current state of system]]:
 +
 +- Visible 0.3 - 1 µm range: under development, testing and buiding [2013-2015]. Ready for full testing end of 2015
 +
 +- Infrared 1 - 4.8µm range: extension planned in 2015-2017 (if EPN2020-RI program accepted)
 +
 +- low temperature: to be tested in cold room down to -20°C (end 2015)
 +
 +  * Characteristics: Micro-Spectro-Gonio_characteristics.pdf **(TBD)**
 +
 +  * Article: 
 +
 +**Availability to community:**
 +
 +//**2016-2017:**//
 +
 +- Technical improvements/calibration (40%) 
 +
 +- IPAG + associated laboratories measurements (60%)
 +
 +//**after 2017:**//
 +
 +- Technical improvements/calibration (20%) 
 +
 +- IPAG + associated laboratories measurements (60%)
 + 
 +- open as facility or to specific collaborations w. funding (20%) 
 +
 +----
 +
 +**References:**