Paper detail

Coherent bremsstrahlung at the BEPC collider

Coherent bremsstrahlung (CBS) is a sopecific type of radiation at colliders with short bunches. In the present paper we calculate the main characteristic of CBS for the BEPC collider. At this collider $d N_γ\sim 3\cdot 10^8 dE_γ/E_γ$ photons of CBS will be emitted for a single collision of the beams in the energy range $E_γ$ smaller than 240 eV. It seems that CBS can be a potential tool for optimazing collisions and for measuring beam parameters. Indeed, the bunch length $σ_z$ can be found from the CBS spectrum because critical energy $E_c \propto 1/σ_z$; the horizontal transverse bunch size $σ_x $ is related to $dN_γ\propto 1/σ_x^2$. Besides, CBS may be very useful for a fast control over an impact parameter $R$ between the colliding bunch axex because a dependence of $dN_γ$ on $R$ has a very specific behavior. It seems quite interesting to investigate this type of radiation on the BEPC collider (for example, in the range of a visible light with the rate about $3 \cdot 10^{14} $ photons per second) and apply it for the fast beam control.