Method and apparatus for regulating the beam current in industrial charge carrier beam apparatus

Claim 3

A method as in claim 1 wherein said controlling step comprises the steps of storing a signal indicative of the peak value of the last processed beam pulse, and comparing the stored pulse amplitude signal with the signal representative of the desired peak amplitude to generate the difference signal.

Claim 4

A method as in claim 1 wherein said controlling step further comprises the step of sampling and storing said difference signal, and varying said pulsed beam current dependent upon said sampled and stored difference signal.

Claim 5

A method as in claim 1 where said peak value determining step comprises sampling the beam pulse amplitude indicative signal at the initial portion of each said measured beam pulse.

Claim 6

A method as in claim 4 further comprising the steps of providing a keying pulse for signal sampling coincidentally with the provision of a charge-carrier beam pulse.

Claim 7

A method as in claim 5, characterized by the pulse widtH of the keying pulses tg being adjusted with respect to the pulse width of a charge-carrier beam pulse tp such that tg tg(max), when tp > tg(max) and tg tp when tp < tg(max), where tg(max) is a nominal keying pulse width.

Claim 8

In combination in apparatus for regulating the beam current in pulsed charge-carrier beam apparatus, means for supplying a pulsed electron beam, controlled beam current pulse amplitude varying apparatus for varying said electron pulses in accordance with a control signal supplied thereto, means for directly inductively measuring the amplitude of the charge-carrier beam about the path of propagation of said pulsating beam, said measuring means including means for providing a signal indicative of said beam amplitude, means for determining the peak amplitude of each measured beam pulse responsive to the signal representative of each such pulse, means for providing a reference signal for establishing a desired pulse amplitude value, and sample and hold and difference determining means responsive to the difference between the peak value of a measured current pulse and said reference signal supplied by said source thereof for supplying a beam pulse amplitude controlling signal to said controlled beam current pulse amplitude varying means.

Claim 9

In combination in apparatus for regulating the beam current in pulsed charge-carrier beam apparatus, means for supplying a pulsed electron beam, controlled beam current pulse amplitude varying apparatus for varying said electron pulses in accordance with a control signal supplied thereto, means for directly inductively measuring the amplitude of the charge-carrier beam about the path of propagation of said pulsating beam, said measuring means including means for providing a signal indicative of said beam amplitude, means for determining the peak amplitude of each measured beam pulse responsive to the signal representative of each such pulse, means for providing a reference signal for establishing a desired pulse amplitude value, and sample and hold and difference determining means responsive to the difference between the peak value of a measured current pulse and said reference signal supplied by said source thereof for supplying a beam pulse amplitude controlling signal to said controlled beam current pulse amplitude varying means.

Claim 10

A combination as in claim 7 wherein said sample and hold and difference determining means comprises sample and hold means for preserving the peak value of each pulse generated by said pulse measuring means, and difference amplifier means operating upon the output of said sample and hold means and the output of said desired value reference source.

Claim 11

A combination as in claim 7 wherein said sample and hold and difference determining means comprises difference amplifier means responsive to the outputs of said measuring means and said desired value source means, and sample and hold means responsive to the output of said difference amplifier means for controlling said controlled beam current pulse amplitude varying means.

Claim 12

A combination as in claim 8 further comprising pulse supplying means for causing said controlled beam current apparatus to generate beam current pulses, and means responsive to each said pulse supplied by said pulse generating means for supplying a control pulse to said sample and hold means causing said sample and hold means to operate in a sample mode.

Claim 13

A combination as in claim 9 further comprising pulse supplying means for causing said controlled beam current apparatus to generate beam current pulses, and means responsive to each said pulse supplied by said pulse generating means for supplying a control pulse to said sample and hold means causing said sample and hold means to operate in a sample mode.

Claim 14

A combination as in claim 7 wherein said measuring means comprises coil means disposed about the beam propagating path for inductive coupling to said beam.