CTIO 1.0M 2DFRUTTI SPECTROGRAPH
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  Instrument Overview                                                         
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    The Boller & Chivens fast uv-transmitting image tube spectrograph         
    was                                                                       
    used at the f/10 focus of the 1.0m telescope.                             
                                                                              
    Plate Scale (at f/10 focal plane)      19.5 arcsec/mm                     
    Slit Length     19mm mm, 370 arcsec                                       
    Collimator Focal Length         900 mm                                    
    Point source collimated beam diameter   90 mm                             
    Collimator-to-Camera Angle      49 degrees                                
    Grating size    128102 mm                                                 
    Camera Focal Length     140 mm                                            
    Demagnification         6.455                                             
    Plate Scale (at detector)     125 arcsec/mm                               
                                                                              
    The 2D-Frutti was a two-dimensional photon counting detector,             
    originally developed by Steve Shectman then of the Mt Wilson and          
    Las Campanas Observatories. The sensitivity of this detector is           
    determined by the S-20 photocathode of the Carnegie image tube            
    which provides the first intensification stage.  This peaks at ~          
    4200A, declining slowly toward the red, so that 7300A can be taken        
    as its red limit.  In the UV, the 2D-Frutti was sensitive down to         
    the atmospheric cutoff (3200A).  The 2D-Frutti offered a format up        
    to 1.5-M pixels, zero readout noise, and low dark current ( < 1           
    count/pixel/hour for 1x1 binning). Conversely the 2D-Frutti could         
    be irreversibly damaged by over illumination and count rates must         
    be further limited to typically < 1 cts/pixel/second, because of          
    coincidence losses. Even with these precautions, the 2D-Frutti was        
    not really all that linear.