Roman S. Dygdała

Real-time multichannel scaler measurement of oscillator instabilities

This article describes measurement of oscillator instabilities by a method using the real-time multichannel scaler (RTMS). A theoretical model for such application is also considered. The general problem of the oscillator instability measurements in time domain is discussed. The results of oscillator instability measurements using the real-time multichannel scaler and a time interval analyzer are compared. The full range of application of this method is up to 7E-7 and depends strongly on the RTMS construction. We present the results of oscillator instability measurements of the order of 3E-5, using the RTMS with a resolution of 3.13 ns and the range of operation 3.28 ms.

Counting errors in a real-time multichannel scaler

In this article the problem of errors arising from a specific design of a real-time multichannel scaler is presented. The dead-times error, double-pulse error, and the error due to the gate width modulation are discussed. The absolute values of the systematic errors of the gate widths of a single channel are of the order of hundreds of picoseconds, making for a severe problem when the gate is small. The problem is overcome by a floating allocation of the gates. This method leads to a decrease in the differences between the variances of the number of counts for all time channels and as a consequence improves the precision of the measurements.

X-Ray Study of Nd: YAG on (111)-Oriented Si Obtained by Pulsed Laser Deposition

Yttrium aluminium garnet thin films doped with neodymium have been prepared by Pulsed Laser Deposition method on (111)-oriented Si substrates. The substrate was heated up to temperature in the range between 200 and 600 degrees C. Obtained films were then characterized both by x-ray diffraction method using Siemens D5000 diffracto-meter and radioluminescence spectroscopy.

X-ray characterization of PbSe/Si layers grown by pulsed laser ablation method

PbSe thin layers were grown by pulsed laser deposition. The layers were obtained on Si substrates at temperature 45K to 650K. The structure of the layers and its lattice parameters were estimated from the X-ray diffraction measurements. The strong intensity of (200)-PbSe peak indicates a self-texture preference in the c-axis direction.

Growth of Nd:YAG films by the pulsed laser deposition method

Abstract This work presents X-ray diffraction results about the structural properties of thin yttrium aluminum garnet films doped with neodymium. For this purpose, series of samples on silicon substrates were made by the pulsed laser deposition method at various deposition conditions. Successful growth was achieved as long as the substrate temperature was maintained at least at 450 °C. Applied bias was found to exert a detrimental effect on the quality of the films. Laser-produced plasma plume of Y 2 O 3 investigations by means of time-of-flight mass spectrometer were also performed.

Investigation of plasma plume expansion due to laser ablation of Pb

A time-of-flight (TOF) mass spectroscopy technique has been used to investigate the expansion dynamics of ionized atoms and clusters ejected from lead target by ultraviolet laser ablation. An angular distributions if ionic species are presented as well as their influence on the deposited film thickness profile is discussed. The influence of the bias voltage of the intake aperture of spectrometer on TOF spectra has been studied. The TOF spectra of ablated Pb-target and the observed Pvn+(n=2-6) peaks are presented. The angular distribution of the mass of ejected ions is described by cosp(θ).