A robust empirical correction formula has been developed for the approximation of Lorentzian widths, using a known spectrometer bandpass, in instrument-broadened Voigt bands in optical spectra. The relationship between analytically calculated [(w(Voigt) - w(Lorentz))/w(Gauss)] and [w(Voigt)/w(Gauss) - 1] values (where w is the full width at half-maximum [FWHM]) is analyzed to derive the formula...

A new detector geometry is described with relatively high gamma ray energy resolution at room temperature. The device uses the geometric weighting effect, the small pixel effect and the Frisch grid effect to produce high gamma ray energy resolution. The design is simple and easy to construct. The device performs as a gamma ray spectrometer without the need for pulse shape rejection or correctio...

We have designed a laser system for the Linac Coherent Light Source rf photoinjector consisting of a Ti:Sapphire oscillator and 2 amplifiers using Chirped Pulse Amplification. The output after tripling will be 0.5 mJ tunable UV pulses at 120 Hz, with wavelength around 260 nm, pulsewidth of 10 ps FWHM and 200 fs rise and fall times. Amplitude stability is expected to be 1% rms in the UV and timi...

We constructed an ultrahigh-throughput, high-resolution ultraviolet (UV) Raman spectrograph that utilizes a high-efficiency filter-stage monochromator and a high-dispersion Echelle spectrograph. The spectrograph utilizes a total of six mirrors and two gratings, with an overall efficiency at 229 nm of ~18%. The limiting resolution of our spectrometer is 0.6 cm⁻¹ full width half-maximum (FWHM), a...

Epitaxial GaN films were grown by metal organic chemical vapor deposition (MOCVD) on functionalized epitaxial graphene (EG) using a thin ( 11 nm) conformal AlN nucleation layer. Raman measurements show a graphene 2D peak at 2719 cm 1 after GaN growth. X-ray diffraction analysis reveals [0001]-oriented hexagonal GaN with (0002) peak rocking curve full width at the half maximum (FWHM) of 544 arcs...

A relatively new photodetector, the silicon photomultiplier (SiPM), is well suited for PET applications. It has similar sensitivity and gain to the industry standard photomultiplier tube (PMT), but has advantages such as smaller size and insensitivity to magnetic field. These properties make this detector an active area of research in the PET field. I will study a simplified setup, comprised of...

The CSPD-1 y-ray vision system has been constructed for the energy range from 100 keV up to a few MeV, which encompasses most energies of y-ray radiation from the radioactive nuclides of interest t o nuclear facilities. The angular resolution of the system can be varied from about 7" down to 3" FWHM. The energy resolution at 662 keV is 6.8% or 8.9% FWHM depending on which of the two detectors a...

This paper proposes a metallic hole array of a rectangular converging-diverging channel (RCDC) shape with extraordinary transmission. We use a three-dimensional (3D) finite element method to analyze the transmission characteristics of two-dimensional metallic hole arrays (2D-MHA) with RCDC. For a straight channel MHA, when the aperture size is reduced, the transmission peaks have a blue-shift. ...

Background Currently used techniques to quantify late gadolinium enhancement (LGE) include an intensity threshold 5 standard deviations (5-SD) above normal myocardium and the full width at half maximum (FWHM) of the histogram [1,2]. Validation of these segmentation schemes can be performed ex vivo using tetrazolium tetrachloride (TTC). However, no analogous gold standard metric exists in vivo. ...

Solstice is a new concept of gamma camera designed to use the better energy resolution typically available in solid-state detectors. To that purpose, an array of 88 Cadmium Zinc Telluride (CdZnTe or CZT) crystals was characterized for gamma ray detection performance. The bias voltage was applied to the single electrode cathode side of the crystal (radiation side). The anode side of the individu...