Diagnostics for Electron Cloud Measurements in CESR

Clouds of low energy electrons frequently build up within the beam chambers of particle accelerators. In many cases, electron cloud effects (ECEs) cause beam instabilities and degradation of performance. This is of particular concern for high intensity positron rings, in which ECEs can lead to emittance blow-up. Understanding and mitigating electron cloud build up is thus of particular importance in designing the positron damping ring of the International Linear Collider. To this end, electron cloud studies carried out in the Cornell Electron Storage Ring (CESR), beginning with a series of indirect measurements (tune shift, etc), and continuing with the installation of EC diagnostics are intended to allow direct measurement of the cloud density and energy spectrum. Such measurements can potentially provide much greater insight into the physics underlying the development of the electron cloud. As a first step in this stage of the project new diagnostic equipment has been added to the storage ring. This report documents the initial tests of these instruments and their readout electronics.