Optimization of electron storage ring focusing system for the maximum of injection efficiency
Оптимізація структури фокусування накопичувального кільця електронів для одержання максимальної ефективності інжекції
Макарчук О.П. (науковий керівник – к.ф.-м.н. Щербаков О.О.)

The using of intense X-ray beams offers great opportunities for investigations in a high ener​gy physics, nuclear physics, medicine, biology etc. The such source is X-ray generator “NESTOR” [1] located in the National Science Center “Kharkiv Institute of Physics and Tech​nology”. The experimental facility is accelerating storage complex, which contains of a lot of systems and subsystems. The aim of this facility is to create an intensive source of gamma radia​tion by inverse Compton scattering of the laser beam on the relativistic electron beam [2].
This paper is devoted to study and optimize of the storage ring focusing system by computer modeling program – MAD‑X [3]. As well the studying was satisfied to find out effect of errors in lattice of magnetic elements of the storage ring for the electron beam dynamics.
An electron beam is injected into the storage ring by pulsed magnet (inflector) at the distance of 16 mm from the equilibrium orbit. Horizontal measure of physical aperture in the storage ring is ±38 mm and vertical aperture is ±13 mm. The gap between the inflector electrodes is 8 mm. Therefore vertical aperture in the injection point is ±4 mm. In the injection point horizontal aper​ture is ±20 mm, this leads to beam’s shift and it’s loss on the vacuum chamber.
Random errors were set for 20 quadrupole magnetic lenses and 4 bending magnets during the computer simulation. These errors led to some standard deviation of the beam relatively to the equilibrium orbit.
The simulation showed that with given errors about 70% of cases the storage of particles does not occur – particles are lost rather quickly (before the 60th turn) on physical apertures, including the aperture of inflector (80% of all lost particles). The storage exists in 30% of cases. The maximum achieved efficiency of storage is 25%, but on the average it is 12%.
The results of this work will be used to increase the electron injection efficiency into the X-ray generator “NESTOR”.
References

1. Zelinsky, V. Androsov, O. Bezditko, ,et al, The First Results of the NESTOR Commissioning , http://accelconf.web.cern.ch/AccelConf/IPAC2013/papers/mopea063.pdf
2. E.V.Bulyak, P.I.Gladkikh, Yu.Grigor’ev, et al, - “A Compact X-ray Source Based on Compton Scattering”, Nuclear Instruments & Methods, A467-468 (2001), 88-90
3. H. Grote, F. Schmidt “The MAD-X Program. User’s Reference Manual”, CERN – AB-2004-027-ABP