Patent ID: 8886495

Claim:
An apparatus for obtaining diagnostic information about a particle beam circulating in an accelerator, comprising: a) for at least one location on a circumference of a vacuum chamber comprising a part of the accelerator, at least one fixed conducting electrode disposed inside the vacuum chamber; b) for each fixed conducting electrode, a lead connected thereto; and c) at least one feedthrough on a surface of the vacuum chamber; wherein the vacuum chamber encloses an evacuated region; wherein the vacuum chamber encircles a portion of an induction core; wherein the vacuum chamber comprises an electrically conductive portion and a non-conducting gap; wherein each fixed conducting electrode communicates through the lead connected to it to information gathering means disposed outside the vacuum chamber; wherein each lead passes from inside the vacuum chamber to outside through a feedthrough; and wherein each fixed conducting electrode is fixed in location, and is disposed so as to be in position to sense electromagnetically the particle beam circulating in the evacuated region in the vacuum chamber and accelerated by a voltage imposed across the non-conducting gap, and is disposed so as to not to intercept the particle beam.