Storage Rings Parameters
Prerequisite to the operation of an electron storage ring as a primary source standard is - in addition
to sufficient stability of the storage ring - the knowledge of the parameters needed for the calculation.
The spectral photon flux ΦE for a photon energy E is given by the Schwinger equation which
can be expressed schematically as:
The storage ring parameters are:
- electron beam current I,
- electron energy W,
- magnetic induction at the source point B,
- electron beam effective vertical size Σy.
The storage rings parameters have to be measured with high accuracy in order to calculate the spectral output with a low uncertainty. In practice the spectral photon flux through an aperture is calculated and therefore also the emission angle Ψ and the geometry parameters determining the angular acceptance have to be measured, i.e. the distance from the source point d and the aperture size (e. g. a • b for a rectangular aperture).
- electron beam current I,
- electron energy W,
- magnetic induction at the source point B,
- electron beam effective vertical size Σy.
The storage rings parameters have to be measured with high accuracy in order to calculate the spectral output with a low uncertainty. In practice the spectral photon flux through an aperture is calculated and therefore also the emission angle Ψ and the geometry parameters determining the angular acceptance have to be measured, i.e. the distance from the source point d and the aperture size (e. g. a • b for a rectangular aperture).
last update: 2011-09-30
