Exotic crystal spectrometer

A different method became available with modern meson factories, where the characteristic X-radiation from exotic atoms can be studied under optimized conditions and with reasonable count rates. Such experiments require the use of high-intensity external beam lines together with a particle concentrator like the cyclotron trap and a high-resolution low-energy crystal spectrometer. 

The drawback of a high-resolution crystal spectrometer is a rather low efficiency. Therefore, a suitable preparation of the X-ray source is mandatory as are high line yields of the exotic atom transitions by using gas targets with pressures as low as possible. 

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