introduction magnetic fields are capable of altering the trajectory of electron beams andcan be used in radiation therapy.theaim of this study was to produce regions with dose enhancement and reduction in the medium. materials and methods the ndfeb permanent magnets were arranged on the electron applicator in several configurations. then, after the passage of the electron beams (9 and 15 mev va...

background: field matching problems in abutting electron fields can be managed by using spoilers. objective: the aim of this study was to design a monte carlo framework for the assessment of spoiler application in abutting electron fields. methods: a siemens primus treatment head was simulated for a 5 mev electron beam using beamnrc and dosxyznrc, egsnrc user codes. validation of beam model was...

A novel single electron pump based on individual molecules (a single wall carbon nanotube) is discussed in terms of the hybrid superconducting-normal conducting pumping principle. A concept demonstration device has been built based on a carbon nanotube contacted by Nb-Ti leads. Charge current quantization is achieved through rf modulation of the back gate voltage. The device is able to transfer...

Terahertz (THz) NH3 lasing with optical pumping by electron-beam-sustained discharge “long” (?100 µs) CO2 laser pulses was obtained. The emission and the of pump were simultaneously measured nanosecond response time. duration its delay respect to pulse for various energies. For line 9R(30), three wavelengths 67.2, 83.8, 88.9 µm recorded. 9R(16), only a single wavelength 90.4 detected.

2014 The detection of optical resonances by observation of the fluorescence light emitted from a fast atomic beam of Na interacting with a collinear laser beam is limited in sensitivity by optical pumping processes. In the experiment reported here, we take advantage of the optical pumping by using a second collinear laser beam, achieving then a gain in fluorescence signal. The effects of the la...

hdpe monofilaments were obtained using different extruders and drawn by post-extruder equipments. after solidification, drawn and undrawn monofilaments (draw ratio 7:1) were irradiated with 10 mev electron beams in air at room temperature at 25, 50, 75, 100 and 125 kgy dose ranges to induce a network structure. hdpe crosslinking was studied on the basis of gel content measurements. the fibers w...

We present an update on the estimate of the growth time of the multi-bunch transverse instability in the PEP-II collider arising from the interaction of the positron beam with the accumulated electron cloud. We estimate the contributions to the growth rate arising from the dipole magnets and from the pumping straight sections. We emphasize those quantities upon which the instability is most sen...

A high-density ultracold spin polarized atomic hydrogen jet’ will be used as an internal target for the experiments NEPTUN and NEPTUN-A,2 which will study spin effects in proton-proton scattering at energies of 400 GeV and 3 TeV at the UNK accelerator being built at Protvino, USSR. The ultimate intensity goaI of this jet is a polarized beam of 10” atoms/s. In order to keep the vacuum pressure i...

We report clear experimental evidence for second harmonic generation at hard x-ray wavelengths. Using a 1.7 Å pumping beam generated by a free electron laser, we observe second harmonic generation in diamond. The generated second harmonic is of order 10 times the background radiation, scales quadratically with pump pulse energy, and is generated over a narrow phase-matching condition. Of import...