Unipolar blocking method and apparatus for monitoring electrically charged particles

An apparatus for monitoring an electrically charged particle pulse moving along a predetermined path, said apparatus comprising:

• charged particle pulse accelerating means for projecting the electrically charged particle pulse along the predetermined path;
• a plurality of toroidal coils, wherein each of said toroidal coils defines a respective opening therethrough with each of said openings positioned along the predetermined path, and wherein each of said toroidal coils generates a bipolar signal responsive to the electrically charged particle pulse passing through said respective opening, said bipolar signal comprising a first portion having a first polarity and a second portion having a second polarity;
• unipolar blocking means connected to each of said toroidal coils for passing said first portion of each of said bipolar signals having said first polarity and for blocking said second portion of each of said bipolar signals having said second polarity;
• and
• monitoring means connected to said unipolar blocking means for generating an output signal representative of a predetermined characteristic of the particle pulse based upon said first portions of said bipolar signals.

A method of monitoring an electrically charged particle pulse moving along a predetermined path, comprising the steps of:

• projecting the electrically charged particle pulse through an opening in at least one toroidal coil thereby generating a bipolar signal comprising a first portion having a first polarity and a second portion having a second polarity;
• passing said first portion of said bipolar signal having said first polarity, while blocking said second portion of said bipolar signal having said second polarity;
• and
• generating an output signal representative of a predetermined characteristic of the particle pulse based upon said first portion of said bipolar signal which is passed by said passing step.