Interaction of an Ultra-Short Laser Pulse and Ultra-Intense with a Dielectric
Oussama Boultif,
Slimen Belghit,
Beddiaf Zaidi,
Abdelaziz Sid
Issue:
Volume 4, Issue 3, September 2018
Pages:
26-34
Received:
6 September 2018
Accepted:
17 September 2018
Published:
7 November 2018
Abstract: In this work, we dedicated to the presentation of our results concerning the evolution of the electron density in the conduction band and the optical damage threshold (OBT). A study of the influence of the initial electronic density on the electron density in the conduction band and on the threshold of optical damage will also be presented. The main objective of this work is the theoretical study of optical damage of dielectric Materials like: Silicate by using a technique based on ultra-short and high-density laser pulses. The mains theoretical models about the OBT technique given in the literature are also studied. A new theoretical model with several improvements is proposed. This model takes into account the recombination’s mechanism with three holes. New numerical software has been developed in order to solve the PDE systems of our theoretical model using MATLAB simulation. The contribution of different mechanisms with OBT has been studied numerically. The obtained results showed that recombination mechanism with three holes plays an important role to estimate the density of free electrons and the OBT. We showed in our model that the recombination mechanisms reduce the electron density in the band of conduction is therefore increasing the threshold of optical damage (OBT). The predictions of the code developed in this study have been successfully compared to different experimental measurements of thresholds of breakdown in silica. The found results have a good agreement with experimental results.
Abstract: In this work, we dedicated to the presentation of our results concerning the evolution of the electron density in the conduction band and the optical damage threshold (OBT). A study of the influence of the initial electronic density on the electron density in the conduction band and on the threshold of optical damage will also be presented. The mai...
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Treatment of Radiological Medical Waste Using Concrete Cubic Molds
Ali Abdulwahab Ridha,
Lara Adnan Kadhim,
Basim Abdlsattar Hussain
Issue:
Volume 4, Issue 3, September 2018
Pages:
35-39
Received:
8 September 2018
Accepted:
15 October 2018
Published:
13 November 2018
Abstract: Concrete cubic molds were made and manufactured using a fixed percentage of cement and sand to be as a container for the radiological medical waste in order to prevent radiation during the transfer of radioactive waste from hospitals to their own landfill sites to preserve the safety of people and the environment from radiation pollution. The maximum dose rate was 173.744 µSv/h in NHTc2 sample measured using RAD EYE B20 dosimeter, which has a very high activity as a medical waste (28.568 µCi), while the lowest dose value 0.297 µSv/h and activity 0.041 µCi was for MCI4 sample, except the dead samples which less than detection limit for the NaI(Tl) system. Also, the efficiency calculations of manufactured molds with thickness 3 cm were done by using Ba-133 and Cs-137 as a point source, because of the energies of these sources are close to that for I-131 and Tc-99 m exist in the medical waste samples. The shielding percentages were calculated and have very high values with using concrete molds, and the dose rate decreases with increasing the sand in the mold. Measurement of resistivity to compression for the molds were done to acknowledgment the strength to hold radiological waste through transfers or store of these kinds of waste. We found that the increase of the cement percentage (chosen 10, 20 and 30%) leads to increasing the mold strength.
Abstract: Concrete cubic molds were made and manufactured using a fixed percentage of cement and sand to be as a container for the radiological medical waste in order to prevent radiation during the transfer of radioactive waste from hospitals to their own landfill sites to preserve the safety of people and the environment from radiation pollution. The maxim...
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