Measurement of chromaticity-energy spread product by transversely kicking the beam

A method for measuring the product of the chromaticity and the energy spread of a stored electron beam is presented. The technique involves observing the free betatron oscillations resulting from a short kick to the stored beam. Because of the positive chromaticity, the betatron oscillation amplitude is modulated. The ratio of maximum to minimum modulation amplitude is proportional to the product of the chromaticity and the energy spread. If the chromaticity is known, this method provides a useful tool for calculating the energy spread. The advantages and the disadvantages of the method are also discussed. Experimental results are given, including comparison with energy spread values obtained from direct measurement of the bunch length. It is concluded that the proposed method is especially attractive in situations where other methods may be difficult to implement, e.g. trying to measure the energy spread by measuring the bunch length when the bunches are very short