Treating shallow tumors with a homogeneous dose while simultaneously minimizing the dose to distal critical organs remains a challenge in radiotherapy. One promising approach is modulated electron radiotherapy (MERT). Due to the scattering properties of electron beams, the commercially provided secondary and tertiary photon collimation systems are not conducive for electron beam delivery when s...

Most of cancer treatment Radiation Therapy (RT) machines rely on a linac as the source of the treatment beam which can be an electron beam or an X-ray beam. In either case, an approach to vary the energy of the linac’s output beam may be needed to target cancer tumors at different depths. Additionally, some of the Image Guide Radiation Therapy (IGRT) approaches use the linac as the source of bo...

It is now well established that laser plasma acceleration (LPA) is an innovative and good candidate in the beam acceleration field. Relativistic beams are indeed produced up to several GeV but their quality remains to be demonstrated in the highly demanding case of free-electron lasers (FELs). Several experiments have already shown the feasibility of synchrotron radiation delivery based on LPA ...

The Advanced Photon Source was commissioned in March 1995 to provide high-brightness ultrastable x-ray photon beams to its user community. The original beam stability specifications were that the source points not move more than 4.5 microns rms vertically and 17 microns rms horizontally. Reductions in coupling, together with planned reductions in emittance and increasing beamline user sophistic...

To maintain gain in the proposed 100 m long linac-driven Linac Coherent Light Source (LCLS) Free Electron Laser (FEL) undulator, the electron and photon beams must propagate colinearly to within -5 urn rms over distances comparable to the 11.7 m FEL gain length in the 6 mm diameter undulator vacuum chamber. We have considered a variety of intercepting and non-intercepting position monitor techn...

A parasitic electron beam facility has been developed at the Mark III linear accelerator, Stanford University. The beam has been used both for physics experiments and for counter and spark chamber tests, even though the beam intensity is very low. A tagged photon beam was installed as part of the facility. A description of the two beams and a short discussion of the applications of these beams ...

PURPOSE Since the first publications on intensity modulated radiation therapy (IMRT) in the early 1980s almost all efforts have been focused on fairly time consuming dynamic or segmental multileaf collimation. With narrow fast scanned photon beams, the flexibility and accuracy in beam shaping increases, not least in combination with fast penumbra trimming multileaf collimators. Previously, expe...

We measure the absolute absorption cross section of molecules using a matter-wave interferometer. A nanostructured density distribution is imprinted onto a dilute molecular beam through quantum interference. As the beam crosses the light field of a probe laser some molecules will absorb a single photon. These absorption events impart a momentum recoil which shifts the position of the molecule r...