Search results for "Pulse duration"
showing 10 items of 54 documents
<title>Structual changes of the PLZT ceramics irradiated by high-current pulsed electron beam</title>
2003
First time comprehensive study of high-current pulsed electron irradiation effects on the structural, optical and dielectric properties of relaxor (Pb(1-x)Lax)(Zr0.65Ti0.35)1-x/4O3 ceramics with x = 4 and 9.75 at.% have been provided. The electron beam had the following parameters: energy E = 250 keV, current density I = 1000 A/cm2, pulse duration τ = 300 ns, beam density - 1015 electrons/cm2 per pulse. Infrared reflectivity spectra in the region of 100 ÷ 2000 cm-1 were obtained in virgin, irradiated by 1500 pulses. The reconstruction of perovskite ABO3 structure in irradiated samples has been studied by complex use of X-ray and neutron scattering and IR spectroscopy techniques revealing th…
Determination of Kerr and two-photon absorption coefficients of ABI thin films
2018
This material is based upon work supported by the ERDF 1.1.1.1 activity project Nr. 1.1.1.1/16/A/046 “Application assessment of novel organic materials by prototyping of photonic devices”
Q-switched mode locking noise-like pulse generation from a thulium-doped all-fiber laser based on nonlinear polarization rotation
2021
Abstract Q-switched mode locking (QML) noise-like pulse (NLP) emission from an all-fiber thulium-doped laser based on the nonlinear polarization rotation effect is reported. The QML emission is obtained in a cavity with net anomalous dispersion in a pump power interval in between the CW laser threshold and the threshold of the NLP regime. Highest-energy QML pulses were observed with a repetition rate of 812 kHz with a pump power of 520 mW at the optical wavelength of 1881.09 nm. A maximum overall energy of 460 nJ at an average output power of 6.4 mW was reached, which corresponds to a burst of mode-locked noise-like sub-pulses with 8.7 ns of pulse duration within a QML envelope of 11 µs. Th…
Auto-Adaptive Trigger and Pulse Extraction for Digital Processing in Nuclear Instrumentation
2015
International audience; This paper presents a novel auto-adaptive method for pulse triggering and extraction. Pulse triggering uses a threshold that must be placed as close as possible to the noise level. We do this by means of an adaptive threshold level based on real-time noise level estimation. A dynamic estimation of the pulse length is also used for pulse selection. The proposed approach is largely insensitive to noise and enables autonomous extraction of pulses regardless of their shape, height or length. The proposed approach can be used with numerous types of detectors from an analog-to-digital converter, and can be used in conjunction with various pulse processing techniques such a…
First laser ions at an off-line mass separator of the ISAC facility at TRIUMF
2004
For efficient and in particular for selective production of radioactive ion beams at on-line mass separator facilities the technique of resonance ionization laser ion sources (RILIS) has become the most powerful tool. In facilities like ISOLDE at CERN they nowadays represent the most commonly used type of ion source for rare short-lived isotopes, delivering highest suppression of isobaric contaminations. For a first off-line demonstration preparing the development and installation of such a laser ion source at the new ISAC facility at TRIUMF in Vancouver (Canada), an all solid state laser system developed at the University of Mainz (Germany), was transferred and tested there at an off-line …
Comparison of LIBS results on ITER-relevant samples obtained by nanosecond and picosecond lasers
2019
This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement number 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. Work performed under EUROfusion WP PFC.
High-gradient testing of an $S$-band, normal-conducting low phase velocity accelerating structure
2020
A novel high-gradient accelerating structure with low phase velocity, $v/c=0.38$, has been designed, manufactured and high-power tested. The structure was designed and built using the methodology and technology developed for CLIC $100\text{ }\text{ }\mathrm{MV}/\mathrm{m}$ high-gradient accelerating structures, which have speed of light phase velocity, but adapts them to a structure for nonrelativistic particles. The parameters of the structure were optimized for the compact proton therapy linac project, and specifically to 76 MeV energy protons, but the type of structure opens more generally the possibility of compact low phase velocity linacs. The structure operates in S-band, is backward…
Nonlinear spectral compression in fibre as a power-limiting device
2017
Spectral compression (SC) by self-phase modulation in optical fibre has been known for a long time and has since been reported for various parameters [1]. In this paper, we analyse the impact of amplitude fluctuations and a degraded optical signal-to-noise ratio (OSNR) of the seed pulses on the SC process by means of extensive nonlinear Schrodinger equation numerical simulation. Remarkably, our results show that the SC is rather stable against these pulse degradation factors, thereby revealing its potential for use in the context of optical regeneration of intensity-modulated signals. We therefore propose an optical scheme combining SC with an optical bandpass filter (OBPF) centred at the c…
Development and test of iron-free quadrupole lenses with high magnetic flux densities
2003
Abstract Iron-free magnetic quadrupole lenses have been developed for the focusing of energetic bunched heavy-ion beams. These devices are operated in a pulsed mode and provide very strong magnetic fields. A magnetic flux density of more than 14 T has been reached in a 100 mm long quadrupole with a 20 mm wide aperture, which corresponds to a magnetic flux density of ∼1400 T/m. The pulse duration of the applied electric current is approximately 300 μs with a flat top of several μs. The calculated and measured field properties of the quadrupoles are presented. In a first test experiment with a fast-extracted 650 MeV/u 197 Au 79+ beam (bunch length ∼500 ns) at GSI the focusing properties could…
The nonlinear optical loop mirror: soliton and noise-like pulse emission in a figure-eight fiber laser
2021
In this article, a symmetrical nonlinear optical loop mirror (NOLM) exhibiting a polarization-dependent transmission is evaluated to generate optical pulse emission in a figure-eight fiber laser in the soliton and noise-like pulse (NLP) regimes. The NOLM structure relies on a 50:50 fiber coupler, a loop with highly twisted single-mode optical fiber and a quarter-wave retarder (QWR) to break the polarization asymmetry. The pulse operation regime is determined by properly adjusting the NOLM low-power transmission, which is easily realized by the rotation of the QWR angle. Soliton pulses of 1.48 ps pulse duration and peak power of 18 W were observed with a peak to peak separation of 1.25 µs, c…