A focal plane array of high-pressure gas scintillation proportional counters (GSPC) for a balloon-borne hard-x-ray telescope is under development at the Marshall Space Flight Center. These detectors each have an active area of ~ 20 cm, and are filled with a high pressure (10 Pa) xenon-helium mixture. Imaging is via crossed-grid position-sensitive phototubes sensitive in the UV region. The perfo...

The wavefront measurement technique using the Shack Hartmann wavefront sensor has been developed for measurement of wavefront distortion of a SR extraction mirror for the beam profile monitor at Photon Factory. The instrument consists of a multi-lens array ( 8x8 array, 250 mm pitch and focal length of 4.5 mm), a beam expander (20:1), an image relay lens system (1:1), a HeNe laser (633 nm) and a...

A novel optical imaging technique called sonoluminescent tomography was developed for cross-sectional imaging of strongly scattering media noninvasively. Sonoluminescence, which was generated internally in the medium by cw ultrasound, was used to produce a two-dimensional image of an object embedded in a scattering medium by means of raster scanning the medium. The image had a high contrast and...

A new optic system that produces a monochromatic microbeam for both CuKα and CrKα radiation for X-ray diffraction (XRD) has been developed. Multilayer optics technology is a well-known tool to produce a monochromatic micro X-ray beam for XRD. This new optic was combined with a microfocus rotating anode X-ray generator and a cylindrical imaging plate detector to provide a complete dual wavelengt...

We experimentally demonstrate for the first time that a linearly polarized beam is focussed to an asymmetric spot when using a high–numerical aperture focussing system. (1959)] and can only be measured when a polarization insensitive sensor is placed in the focal region. We used a specially modified photodiode in a knife edge type set up to obtain highly resolved images of the total electric en...

The target is cylinder with a length = 7 mm and radius = 5 mm. One face of the cylinder is irradiated with a uranium beam having a particle energy of 400 MeV/u. The beam pulse consists of two bunches, each having a full width at half maximum (FWHM) of 80 ns and the total pule duration is 500 ns. The beam focal spot size (FWHM of the Gaussian power distribution in transverse direction) is assume...

We report on the fabrication and characterization of nanoscale solid immersion lenses (nano-SILs) with sizes down to a subwavelength range. Submicrometer-scale cylinders fabricated by electron-beam lithography are thermally reflowed to form a spherical shape. Subsequent soft lithography leads to nano-SILs on transparent substrates for optical characterization. The optical characterization is pe...

We have performed an experimental and theoretical analysis of the modification of the transverse structure of a probe beam on propagation through an SBS amplifier. The theoretical analysis is based on performing a mode decomposition of the incident fields and determining how each mode amplitude is modified as a result of the nonlinear coupling. For the case of input beams with Gaussian intensit...

The carbon nanotube field emitter array was grown on silicon substrate through a resist-assisted patterning (RAP) process. The shape of the carbon nanotube array is elliptical with 2.0 × 0.5 mm for an isotropic focal spot size at anode target. The field emission properties with triode electrodes show a gate turn-on field of 3 V/μm at an anode emission current of 0.1 mA. The author demonstrated ...

Since the beginning of applications non-destructive testing/evaluation (NDT/NDE) techniques, efforts have been made consistently to improve their detection sensitivity and resolution. In present paper, factors governing lateral resolution in three major NDT viz., ultrasonic testing (UT), x-ray radiographic (XRT), eddy current (ECT) are presented. Furthermore, a review recent advances these tech...