The development of a transmission electron microscope equipped with a field emission gun paved the way for electron holography to be put to practical use in various fields. In this paper, we review three advanced electron holography techniques: on-line real-time electron holography, three-dimensional (3D) tomographic holography and phase-shifting electron holography, which are becoming importan...

PURPOSE Linac-magnetic resonance (MR) systems have been proposed in order to achieve realtime image guided radiotherapy. The design of a new linac-MR system with the in-line 6 MV linac generating x-rays along the symmetry axis of an open MR imager is outlined. This new design allows for a greater MR field strength to achieve better quality images while reducing hot and cold spots in treatment p...

A train of 2-ns micro bunches of longitudinally polarized electrons are generated in a 120-kV DC-gun based injector in the ILC electron source; a bunching system with extremely high bunching efficiency to compress the micro-bunch down to 20 ps FWHM is designed. Complete optics to transport the electron bunch to the entrance of the 5-GeV damping ring injection line is developed. Start-to-end mul...

Minnae Chabwera: NASA Undergraduate Research Scholar Advisor: Dr. Paul Guèye Institution: Hampton University Hampton, VA 23668 Introduction The research conducted under the guidance of Dr. Paul Guèye involved the construction of a Low Energy Electron Accelerator (LELIA) spearheaded by the Physics Department at Hampton University. The aim of this research has been to reactivate a thermionic gun...

The brightness and quality of electron beams in linacbased light sources are ultimately limited by the properties of the beam in the injector. It is thus important to have knowledge of the phase space distribution in addition to the rms emittance to provide an insight into high beam brightness formation mechanisms. A tomography technique has been used to reconstruct the transverse phase space o...

We present the design and initial operation of a 96 kV, 40 A Magnetron Injection Gun (MIG) for a 1.5 MW, 110 GHz gyrotron. A critical parameter for the successful application of this electron gun is the uniformity of electron emission. The I-V curve of emission, at a series of temperatures, is measured. Analysis indicates that the work function of the emitter is 1.6 eV with a (total) spread of ...

We summarize the proceedings of Working Group 1 of the 2005 Energy Recovery Linac (ERL) Workshop. The subject of this working group, the electron gun and injector design, is arguably the most critical part of the ERL as it determines the ultimate performance of this type of accelerators. Working Group 1 dealt with a variety of subjects: The technology of DC, normal-conducting RF and superconduc...

For the generation of intense single and multiple bunches of electrons (>8 nc per bunch) for accelerator studies at SLAC, a high peak current photoemission electron gun has been developed. A gallium arsenide photocathode is illuminated by the optical beam from a frequency doubled, actively mode-locked and Q-switched Nd:YAG laser. The mode-locked optical pulses are of variable, sub-nanosecond wi...

At the Advanced Photon Source (APS) at Argonne National Laboratory (ANL), a free-electron laser (FEL) based on the self-amplified spontaneous emission (SASE) process is nearing completion. Recently, an rf photoinjector gun system was made available to the APS by Brookhaven National Laboratory/Accelerator Test Facility (BNL/ATF). It will be used to provide the highbrightness, low-emittance, and ...

A photoinjector is being constructed in order to produce a pulse train of up to 800 electron bunches, each with 8 nC of charge and a 3.5 ps rms bunch length. The spacing between bunches within a train is 1 s and the train repetition rate is 1–10 Hz. The desired transverse emittance is <20 mm mrad. An rf photo-gun delivers a bunched 4–5 MeV beam which will be accelerated to 14–18 MeV by a 9cell ...