Based on a laser diode, a 12 × 6 photodiode array sensor, and machine learning techniques, a new void fraction measurement method for gas-liquid two-phase flow in small channels is proposed. To overcome the influence of flow pattern on the void fraction measurement, the flow pattern of the two-phase flow is firstly identified by Fisher Discriminant Analysis (FDA). Then, according to the identif...

We have developed a measurement system based on a correlation method to characterize the nonlinearity of a detector's response over a large range of laser pulse energy. The system consists of an excimer-laser source, beam-shaping optics, a beam splitter, a monitor detector, a set of optical filters, and the detector under test. Detector nonlinearities as large as 10% or greater over an entire m...

Existing precision displacement-measuring devices are primarily based on linear encoders (optical or magnetic) or laser interferometers. Most encoders use grating scales and frequency counters, while most interferometers use stabilized lasers and fringe counters. In general, interferometers are more expensive and more accurate than linear encoders. However, there are large gaps in price and per...

Plasma plumes resulting from Nd:YAG laser ablation of copper and Fecralloy (Fe 72.8%, Cr 22%, Al 5%, Zr trace, Y trace) have been analysed simultaneously with Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Mass Spectrometry (LAMS). A commercially available Residual Gas Analyser (RGA) was employed to perform mass spectrometric analysis of the neutral and ionic species created dur...

Requirements for precise digital elevation data (i.e., Digital Elevation Models, or DEMs) of varying levels of detail are being formulated for different fields of application. The degree of detail found in a DEM is usually characterized by the horizontal sample spacing and by the vertical accuracy of the samples. Increased detail is normally associated with increased cost to the user, which fue...

We report on the world’s first experiment of a parallel profile scan of the hydrogen ion (H) beam using a laser wire system. The system was developed at the superconducting linac (SCL) of the Spallation Neutron Source (SNS) accelerator complex. The laser wire profile scanner is based on a photo-detachment process and therefore can be conducted on an operational H beam in a nonintrusive manner. ...