We adopt the Echo-Enabled Harmonic Generation (EEHG) scheme proposed by D. Xiang to design a device to generate intense narrow-band THz radiation based on the Tsinghua Thomson scattering X-ray (TTX) electron beam [1]. In this scheme the 50 MeV electron beam is firstly energy-modulated by two lasers with wavelengths of 800nm and 1560nm respectively. Then the modulated electron beam is sent into ...

introduction bnct is an effective method to destroy brain tumoral cells while sparing the healthy tissues. the recommended flux for epithermal neutrons is 109 n/cm2s, which has the most effectiveness on deep-seated tumors. in this paper, it is indicated that using d-t neutron source and optimizing of beam shaping assembly (bsa) leads to treating brain tumors in a reasonable time where all iaea ...

The Spiral2 driver uses a slow chopper situated in the common section of the low energy beam transport line to change the beam intensity, to cut off the beam in case of critical loss and to avoid hitting the wheel structure of rotating targets. The device has to work up to 10 kV, 1 kHz repetition frequency rate and its design is based on standard power circuits, standard vacuum feed-through and...

Novel compact beam expanders that could be useful for applications such as providing light to flat panel displays are presented. They are based on a planar configuration in which three spatially linear gratings are recorded on one transparent substrate, so as to expand a narrow incoming beam in two dimensions. We present the design and recording procedures along with results, showing a relative...

We observe spectral hole burning in a room-temperature optical fiber pumped by a spectrally broadened pump beam. This beam drives the stimulated Brillouin process, creating an inhomogeneously broadened resonance in the material whose shape can be engineered by tailoring the beam's spectrum. A monochromatic saturating beam "burns" a narrow spectral hole that is approximately 10(4) times narrower...

Using a focused ion beam, we patterned epitaxial graphene on SiC into an array of graphene nanoribbons as narrow as 15 nm by optimizing the Ga(+) ion beam current, acceleration voltage, dwell time, beam center-to-center distance and ion dose. The ion dose required to completely etch away graphene on SiC was determined and compared with the Monte Carlo simulation result. In addition, a photodete...

breeding programs strategies depends on genetical mechanism of selection traits. in the present research, generation mean analysis with joint scaling test was performed to determine the gene action. f1, f2 and f3 generations, derived from roushan and kavir cross along with their parents were sown in a partial lattice design with two replications under stress condition at the research field of s...

The presence of metallic prostheses during external beam radiotherapy of malignancies in the pelvic region has the potential to strongly influence the dose distribution to the target and to tissue surrounded by the prostheses. This study systematically investigates the perturbation effects of unilateral titanium prosthesis on 6 and 15 MV photon beam dose distributions using Gafchromic EBT2 film...

In this article, a linear phased antenna array for beam scanning is considered with a fixed narrow/broad interference out of the scanning region. This interference is aimed to be suppressed by optimizing the positions of array elements while avoiding the rise of maximum sidelobe level (MSLL) during the main beam is scanning within the prescribed region. These two objectives; suppressing the fix...

Sub-Doppler excitation spectroscopy in a collimated cold supersonic beam of 5% NO seeded in argon has been performed with a spectral resolution down to 10 MHz for four vibronic bands within the perturbed B ?X A system of NO . The rotational temperature of about 15 K achieved by adiabatic cooling allows the separation of closely lying vibronic bands which overlap in absorption spectra ...