Terahertz imaging system and associated method

A terahertz imaging system comprising:

• a terahertz light source for emitting a plurality of output pulses across a frequency range at a target, each output pulse having a desired output frequency and a full width half maximum equal to or less than 3% of the desired output frequency;
• a detector for receiving a reflection of each output pulse off the target;
• a controller for analyzing the reflections received by the detector for determining a composition material of the target based on a change in the received reflection at a predefined output frequency;
• a raster magnet assembly for directing x-rays emitted by the terahertz light source at the target;
• and
• a backscatter x-ray detector for receiving the x-rays reflected off the target.

A terahertz imaging system comprising:

• a free electron laser comprising an electron gun, a linear accelerator, and a wiggler magnet, wherein the free electron laser emits a plurality of output pulses across a frequency range at a target, each output pulse having a desired output frequency, wherein the free electron laser further comprises an output coupler defining an opening through which the output pulses are emitted, wherein a size of the opening defined by the output coupler is configured to change to offset any change in gain of an output pulse;
• a beam redirection apparatus for receiving an electron beam after a forward pass through the linear accelerator and the wiggler magnet and changing a direction of the electron beam such that the electron beam makes a reverse pass through the wiggler magnet and the linear accelerator, wherein the reverse pass through the wiggler magnet increases a gain of each output pulse, and wherein the reverse pass through the linear accelerator decelerates the electron beam such that a portion of kinetic energy of the electron beam is recovered by the linear accelerator;
• a detector for receiving a reflection of each output pulse off the target;
• and
• a controller for analyzing the reflections received by the detector for determining a composition material of the target based on a change in the received reflection at a predefined output frequency.

A terahertz imaging system comprising:

• a free electron laser comprising an electron gun, a linear accelerator, and a wiggler magnet, wherein the free electron laser emits a plurality of output pulses across a frequency range at a target, each output pulse having a desired output frequency;
• a beam redirection apparatus for receiving an electron beam after a forward pass through the linear accelerator and the wiggler magnet and changing a direction of the electron beam such that the electron beam makes a reverse pass through the wiggler magnet and the linear accelerator, wherein the reverse pass through the wiggler magnet increases a gain of each output pulse, and wherein the reverse pass through the linear accelerator decelerates the electron beam such that a portion of kinetic energy of the electron beam is recovered by the linear accelerator;
• a detector for receiving a reflection of each output pulse off the target;
• a controller for analyzing the reflections received by the detector for determining a composition material of the target based on a change in the received reflection at a predefined output frequency;
• a raster magnet assembly for directing x-rays emitted by the free electron laser at the target in an x-y pattern;
• and
• a backscatter x-ray detector for receiving the x-rays reflected off the target.

A method of terahertz imaging, the method comprising:

• emitting a plurality of output pulses across a frequency range at a target, each output pulse having a desired output frequency and a full width half maximum equal to or less than 3% of the desired output frequency, wherein emitting the plurality of output pulses comprises changing a size of an opening of an output coupler through which the output pulses are emitted to offset any change in gain of an output pulse;
• receiving a reflection of each output pulse off the target;
• and
• analyzing the received reflections to determine a composition material of the target based on a change in the received reflection at a predefined output frequency.