Provided herein are systems and methods for generating a plurality of different monoenergetic neutron energies using a plurality of interchangeable ion beam targets. In certain embodiments, each of the plurality of ion beam targets is configured to generate a monoenergetic energy value that is at least 100 kiloelectron volts (keV) different from the other ion beam targets. In some embodiments, the ion beam targets are composed of LiF, TiD.sub.1.5-1.8, TiT.sub.1-2, ErD.sub.1.5, ErT, or Li.

A method and apparatus for processing a particle shower using a laser-driven plasma is provided. The method comprises interacting a particle shower with a processing laser-driven plasma stage, the particle shower comprising at least one particle species, wherein the laser is a high-energy, ultra-short pulse laser. In some embodiments, the method comprises accelerating, decelerating, trapping, or collimating the at least one particle species in the processing laser-drive plasma stage. Particularly, the embodiments enable generating high energy particle beams that were only possible using accelerators spanning several hundred meters, in a space of a few meters.

A method and apparatus for processing a particle shower using a laser-driven plasma is provided. The method comprises interacting a particle shower with a processing laser-driven plasma stage, the particle shower comprising at least one particle species, wherein the laser is a high-energy, ultra-short pulse laser. In some embodiments, the method comprises accelerating, decelerating, trapping, or collimating the at least one particle species in the processing laser-drive plasma stage. Particularly, the embodiments enable generating high energy particle beams that were only possible using accelerators spanning several hundred meters, in a space of a few meters.

An N-M tomography system comprising: a carrier for the subject of an examination procedure; a plurality of detector heads; a carrier for the detector heads; and a detector positioning arrangement operable to position the detector heads during performance of a scan without interference or collision between adjacent detector heads to establish a variable bore size and configuration for the examination. Additionally, collimated detectors providing variable spatial resolution for SPECT imaging and which can also be used for PET imaging, whereby one set of detectors can be selectably used for either modality, or for both simultaneously.

In some variations, an interferometric frequency-reference apparatus comprises: an atom source configured to supply neutral atoms to be ionized; an ionizer configured to excite the neutral atoms to form ionized atoms; an ion collimator configured to form a collimated beam of the ionized atoms; probe lasers; and a Doppler laser configured to determine a ground-state population of the ionized atoms, wherein the atom source, the ionizer, and the ion collimator are disposed within a vacuum chamber. Other variations provide a method of creating a stable frequency reference, comprising: forming ionized atoms from an atomic vapor; forming a collimated beam of ionized atoms; illuminating ionized atoms with first and second probe lasers; adjusting the frequencies of the first probe and second probe lasers using Ramsey spectroscopy to an S.fwdarw.D transition of ionized atoms; and determining a ground-state population of the ionized atoms with another laser.

In some variations, an interferometric frequency-reference apparatus comprises: an atom source configured to supply neutral atoms to be ionized; an ionizer configured to excite the neutral atoms to form ionized atoms; an ion collimator configured to form a collimated beam of the ionized atoms; probe lasers; and a Doppler laser configured to determine a ground-state population of the ionized atoms, wherein the atom source, the ionizer, and the ion collimator are disposed within a vacuum chamber. Other variations provide a method of creating a stable frequency reference, comprising: forming ionized atoms from an atomic vapor; forming a collimated beam of ionized atoms; illuminating ionized atoms with first and second probe lasers; adjusting the frequencies of the first probe and second probe lasers using Ramsey spectroscopy to an S.fwdarw.D transition of ionized atoms; and determining a ground-state population of the ionized atoms with another laser.

Multiposition collimation devices and x-ray imaging systems, which include the multiposition collimation devices, are provided. The multiposition collimation device includes a collimator housing and a collimator plate constructed to at least partially block the passage of x-rays. The collimator plate is movable relative to the collimator housing to a first position, corresponding to a first x-ray detector size, and a second position, corresponding to a second x-ray detector size.

Multiposition collimation devices and x-ray imaging systems, which include the multiposition collimation devices, are provided. The multiposition collimation device includes a collimator housing and a collimator plate constructed to at least partially block the passage of x-rays. The collimator plate is movable relative to the collimator housing to a first position, corresponding to a first x-ray detector size, and a second position, corresponding to a second x-ray detector size.

An anti-scatter collimator is for arrangement in a stacked construction with an X-ray detector. In an embodiment, the anti-scatter collimator includes collimator walls arranged adjacently at least along a first direction. The collimator walls are mutually spaced to provide a through-channel between each pair of adjacent collimator walls. The through-channels provided by the arrangement of the multiplicity of collimator walls are at least partially filled with a filler material.

One or more example embodiments of the present invention relates to a fin for collimating therapeutic radiation. The fin comprises a collimation area made of a first material and a holding area made of a second material. Herein, the collimation area and the holding area are pressed together. Herein, the first material is formed to collimate therapeutic radiation. Herein, the holding area can be coupled to an adjustment device for adjusting the fin.