• J.L. Crisp, N. Eddy, I. Kourbanis, K. Seiya, R.M. Zwaska
  Fermilab, Batavia
• S. De Santis
  LBNL, Berkeley, California

Electron cloud density in the Fermilab Main Injector was measured by observing microwave transmission along the vacuum tube. Presence of the electron cloud reduces the velocity of the microwave signal. Both frequency and time domain methods reveal relative cloud density and time evolution. The effect of beam time structure is clearly evident. The accelerator magnetic field effects the distribution of electrons making it difficult to estimate density.

• A. Warner, K. Carlson, L.R. Carmichael, J.L. Crisp, R.W. Goodwin, L.R. Prost, G.W. Saewert, A.V. Shemyakin
  Fermilab, Batavia

Abstract The Fermilab Recycler ring employs an electron cooler to store and cool 8.9-GeV antiprotons. The cooler is based on a 4.3MV, 0.1A, DC electrostatic accelerator (Pelletron) for which current losses have to remain low (~10^-5) in order to operate reliably. The Machine Protection System (MPS) has been designed to interrupt the beam in a matter of 1-2 μs when losses higher than a safe limit are detected, either in the accelerator itself or in the beam lines. This paper highlights the various diagnostics, electronics and logic that the MPS relies upon to successfully ensure that no damage be sustained to the cooler or the Recycler ring.