A compact radio-frequency quadrupole RFQ accelerator for accelerating charged particles, the RFQ accelerator comprising: a bunching section configured to have a narrow radio-frequency rf acceptance such that only a portion of a particle beam incident on the bunching section is captured, and wherein the bunching section bunches the portion of the particle beam; an accelerating section for accelerating the bunched portion of the particle beam to an output energy; and, a means for supplying radio-frequency power.

A hybrid linear accelerator is disclosed comprising a standing wave linear accelerator section (SW section) followed by a travelling wave linear accelerator section (TW section). In one example, RF power is provided to the TW section and power not used by the TW section is provided to the SW section via a waveguide. An RF switch, an RF phase adjuster, and/or an RF power adjuster is provided along the waveguide to change the energy and/or phase of the RF power provided to the SW section. In another example, RF power is provided to both the SW section and the TW section, and RF power not used by the TW section is provided to the SW section, via an RF switch, an RF phase adjuster, and/or an RF power. In another example, an RF load is matched to the output of the TW section by an RF switch.

An insertion device includes first and second magnet arrays facing each other with a gap therebetween, magnet supporting members adapted to support the magnet arrays mounted thereto, a gap driving mechanism for driving the first and second magnet supporting members in the vertical direction for changing the gap size, a driving conjunction mechanism for coupling the gap driving mechanism and the magnet supporting members to each other, compensation spring mechanisms adapted to compensate for attractive forces acting on the first and second magnet arrays, a spring conjunction mechanism for coupling the compensation spring mechanisms and the magnet supporting members to each other, a first supporting frame for supporting the gap driving mechanism, a second supporting frame for supporting the compensation spring mechanisms, and a common base placed on a placement surface, wherein the first supporting frame and the second supporting frame are individually coupled to the common base.

An undulator for a free electron laser includes a pipe for an electron beam and one or more periodic magnetic structures extending axially along the pipe. Each periodic magnetic structure includes a plurality of magnets and a plurality of passive ferromagnetic elements, the plurality of magnets being arranged alternately with the plurality of passive ferromagnetic elements in a line extending in an axial direction. Each of the plurality of magnets is spatially separated from the pipe, and each of the passive ferromagnetic elements extends radially from an adjacent magnet towards the pipe. A spacer element may be provided between the magnets and the pipe to provide radiation shielding for the magnets and/or cooling for the pipe.

An undulator comprises at least M permanent magnet periods arranged sequentially in a transmission direction of electron beams, each of the permanent magnet periods comprises four rows of permanent magnet structures, in which each row comprises N rows of permanent magnet groups, and each row of the permanent magnet groups comprises K permanent magnet units, wherein M, N and K are natural numbers greater than or equal to 1; the four rows of the permanent magnet structures are pairwise matched, then relatively disposed on both sides of the transmission direction of electron beams, and are capable of forming at least one composite magnetic fields by relative displacement, such that elliptically polarized light, circularly polarized light, or linearly polarized light with an arbitrary polarization angle of 0360 is generated when electron beams pass through the composite magnetic fields, and such that velocity directions of electrons are deviated from an axis direction of the undulator.

A method of patterning lithographic substrates, the method comprising using a free electron laser to generate EUV radiation and delivering the EUV radiation to a lithographic apparatus which projects the EUV radiation onto lithographic substrates, wherein the method further comprises reducing fluctuations in the power of EUV radiation delivered to the lithographic substrates by using a feedback-based control loop to monitor the free electron laser and adjust operation of the free electron laser accordingly.

Employing undulator devices as x-ray radiation sources requires expensive and bulky support systems for operation, which are not robust and lead to limited ranges of generated radiation energies. A force-compensated undulator device is described. The device includes an undulator having first and second magnet arrays disposed along a central axis. The first magnet array is translatable along the central axis. The device further includes a compensator unit disposed adjacent to the first magnet array with the compensator unit having a first row of magnets disposed along a compensator axis with the compensator axis being parallel to the central axis, and a second row of magnets disposed along the compensator axis. The first row of magnets is translatable along the compensator axis. The compensator provides magnetic forces that neutralize the system dynamic magnetic forces generated by the undulator.

A Hybrid (SW+TW) Linear Accelerator is disclosed having high beam efficiency and broad energy regulation that is useful for security inspection, non-destructive testing, radiotherapy, and electron beam irradiation of objects. The Hybrid Linear Accelerator (LINAC) provides superior energy regulation, and includes a reversed RF power distribution which substantially improves RF power utilization, thereby eliminating need for an output RF load, and ensuring broad electron beam energy regulation operating in a broad range of input RF power, thereby efficiently running at a variety of input electron beam current intensities at high efficiency. The Hybrid LINAC may be equipped with a fast and/or slow phase shifter and/or a power regulator having a phase shifter and a current regulator, while operating much more efficiently than known LINACS. The Hybrid LINAC permits efficient operation without an external magnetic field, thereby avoiding use of a power-consuming solenoid, consequently reducing cost of production, operation, and maintenance.

A tapering enhanced stimulated superradiant amplification method and system which utilizes a strongly tapered undulator in reaching significant power outputs and conversion efficiencies. TESSA dramatically increases conversion/amplification efficiencies by violently (sharply) decelerating electrons and taking advantage of produced radiation to further drive interaction toward as it takes advantage of produced radiation to further drive interaction to increase overall radiation output. The system and method configures a strongly tapered undulator to operate in a new mode that is above normal input saturation levels to provide an amplified output with unexpectedly high efficiencies and power.

An undulator with a compact construction is provided that reduces weight, complexity and cost. The compact undulator system and methods provides mechanical integrity without compromising magnetic field quality.