US 5,933,335 A · Compact solid state klystron power supply

Abstract

A line type modulator for modulating an RF power device in a medical linear accelerator is described. The modulator employs a low voltage DC power source and a flyback transformer. Current sensing circuitry senses current in the primary winding of the flyback transformer and generates a current sense signal indicative thereof. A solid-state switching stage is coupled between the DC power source and the flyback transformer which electrically connects and disconnects the DC power source and the primary winding in response to a control signal. Control circuitry coupled to the current sensing circuitry and the switching stage generates the control signal in response to the current sense signal. The anode of a charge diode assembly is coupled to the secondary winding of the flyback transformer. A delay element is coupled to the cathode of the charge diode assembly. A pulse forming network is coupled to the delay element and generates an energy pulse. A solid-state switch assembly is also coupled to the cathode of the charge diode assembly and discharges energy stored in the pulse forming network via the delay element in response to a trigger signal. A pulse transformer coupled to the pulse forming network delivers the energy pulse to the RF power device.

Claims21

Dependent claims

A line type modulator for modulating an RF power device in a medical linear accelerator, comprising:

a low voltage DC power source;
a flyback transformer having a primary winding and a secondary winding;
current sensing circuitry for sensing current in the primary winding of the flyback transformer and generating a current sense signal indicative thereof;
a switching stage coupled between the DC power source and the flyback transformer, the switching stage comprising at least one solid-state device for electrically connecting and disconnecting the DC power source and the primary winding of the flyback transformer in response to a control signal;
control circuitry coupled to the current sensing circuitry and the switching stage for generating the control signal in response to the current sense signal;
a charge diode assembly, the anode of which is coupled to the secondary winding of the flyback transformer;
a delay element coupled to the cathode of the charge diode assembly;
a pulse forming network coupled to the delay element for generating an energy pulse;
a solid-state switch assembly coupled to the cathode of the charge diode assembly for discharging energy stored in the pulse forming network via the delay element in response to a trigger signal;
and
a first pulse transformer for delivering the energy pulse to the RF power device, the first pulse transformer having a primary winding coupled to the pulse forming network and a secondary winding for coupling to the RF power device.

8 more elements

A medical linear accelerator, comprising:

an RF power device for generating high power RF pulses;
a line-type modulator coupled to the RF power device for modulating the RF power device, the line type modulator comprising:
a low voltage DC power source;
a flyback transformer having a primary winding and a secondary winding;
current sensing circuitry for sensing current in the primary winding of the flyback transformer and generating a current sense signal indicative thereof;
a switching stage coupled between the DC power source and the flyback transformer, the switching stage comprising at least one solid-state device for electrically connecting and disconnecting the DC power source and the primary winding of the flyback transformer in response to a control signal;
control circuitry coupled to the current sensing circuitry and the switching stage for generating the control signal in response to the current sense signal;
a charge diode assembly, the anode of which is coupled to the secondary winding of the flyback transformer;
a delay element coupled to the cathode of the charge diode assembly;
a pulse forming network coupled to the delay element for generating an energy pulse;
a solid-state switch assembly coupled to the cathode of the charge diode assembly for discharging energy stored in the pulse forming network via the delay element in response to a trigger signal;
a pulse transformer for delivering the energy pulse to the RF power device, the pulse transformer having a primary winding coupled to the pulse forming network and a secondary winding coupled to the RF power device;
a source of electrons;
an accelerator tube coupled to the RF power device and the source of electrons for generating a beam of high energy electrons;
and
a treatment head for receiving the beam of high energy electrons.

13 more elements

Dependencies are inferred from the claim text.

Compact solid state klystron power supply

Life of this patent

Compact solid state klystron power supply

Life of this patent

Abstract

Claims21