Author/Authors :
Adamson، نويسنده , , P and Barrett، نويسنده , , L and Belias، نويسنده , , A and Blake، نويسنده , , A and Cabrera، نويسنده , , A and Falk، نويسنده , , E and Harris، نويسنده , , P.G. and Hartnell، نويسنده , , J and Howcroft، نويسنده , , C and Kordosky، نويسنده , , M and Lang، نويسنده , , K and Lee، نويسنده , , R and Liu، نويسنده , , J and Michael، نويسنده , , D and Morse، نويسنده , , R and Nelson، نويسنده , , J.K and Nichol، نويسنده , , R and Pearce، نويسنده , , G and Ruddick، نويسنده , , K and Smith، نويسنده , , P.N and Symes، نويسنده , , P.A and Thomas، نويسنده , , J and Vahle، نويسنده , , P.L and Webb، نويسنده , , R and Weber، نويسنده , , A and White، نويسنده , , R.F، نويسنده ,
Abstract :
The MINOS light-injection calibration system has been fully documented in a previous article (Nucl. Instr. and Meth. A 492 (2002) 353). Upon commissioning in the MINOS detectors, the system was found to give a non-linear response to variations in the intensity of injected light. The source of this non-linearity has been traced to a small change in the spectrum of the injected light as a function of the current applied to the original blue LEDs, in combination with a rapidly varying spectral response function of the wavelength-shifting fibre used in the detector. Both aspects of the problem have been addressed successfully by use of LEDs with different spectral characteristics, and the system now has a linear response.
