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Wildfires can have severe impacts on humans and nature. One such impact pertains to changes in water quality resulting from the generation and transportation of ash into bodies of water. The quantity and content of this ash can affect the water quality, and thereby the drinking water supply. The Mediterranean region and Portugal specifically, have been, and are increasingly expected to be affected by fire-induced water contamination. Current research has focused on local evaluation of impacts, as well as the global identification of areas at risk. What lacks is the assessment of fire-induced water contamination risk at an intermediate scale, which can be used as a basis for the efficient allocation of efforts mitigating this risk. This study performed a risk assessment of Portuguese reservoirs based on their historical exposure to wildfires, their drinking water dependency and their vulnerability to fire-induced water contamination. A general risk index was established through the creation and combination of hazard and exposure indices, reflecting a reservoirs’ drinking water dependency and historical exposure to wildfire respectively. The former was based on data on the yearly water uptake from drinking water facilities at a reservoir. The latter was based on the processing of 32 years of historical data on wildfires and reflects to which extent and frequency reservoirs’ watershed areas have been burned. This was followed by further analysis at local scale, consisting of (1) a more relevant method of measuring exposure that includes historic reservoir volumes, as well as (2) an exploration of the vulnerability of several water supply systems. This study has produced a nationwide overview of fire-induced water contamination risk as well as of the degree to which the hazard and exposure concepts contribute to this risk. Numerous differences were found regarding the degree to which individual reservoirs are at risk. These can be ascribed to various regional difference

The diffusion processes in tungsten are simulated by using Monte Carlo methods. Measurements of deuterium retention in tungsten are compared to theory. The influence of traps on deuterium retention is investigated. While simulating the atomic structure of tungsten takes a lot of calculation time, a method is introduced that is able to extend the total time that is simulated to weeks. To reach these timescales, the simple diffusion process is treated different than trapping and detrapping. The influence of traps on diffusion processes is demonstrated. Namely, if trap influence is neglected the observed retention behaviour cannot be recreated. Deep traps with trap energies around 1.2 eV keep deuterium trapped for large timescales at room temperature and they have a large effect on diffusion processes. However, it is very unlikely that they fully account for the observed behaviour of deuterium retention. Shallow traps with trap energies around 0.7 eV are shown to slow down diffusion, predicting behaviour that is in accordance with measurements.

Laser-Induced Desorption-Quadrupole Mass Spectrometry (LID-QMS) is a diagnostic method in which a quadrupole mass analyzer is used to measure the amount of material that is desorbed from a sample by firing a spot laser on the surface. An LID-QMS system has been set up at the Target Exchange and Analysis Chamber (TEAC) of the plasma generator Magnum-PSI in order to investigate the first principles of laser-induced desorption of hydrogen isotopes from plasma facing component (PFC) materials. Two LID-QMS experiments with pre-treated targets were conducted in which the local hydrogen and deuterium concentration of the samples was determined. The most important uncertainty in the observed concentrations resulted from the determination of the desorbed area. This area is essential for obtaining the D and H concentrations of the targets but is difficult to determine. Furthermore, a first attempt to perform an absolute calibration of the LID-QMS system at the TEAC was unsuccessful. Fulfilment of this absolute calibration is a priority for further research. The experimental work was supported by theoretical modeling in TMAP7. TMAP7 analysis showed that, for a single 3.0 ms laser pulse on a tungsten (W) surface, desorption percentages are higher than 90% for maximum surface temperatures > 1300 K.

An advanced Thomson scattering system has been built for a linear plasma generator for plasma surface interaction studies. The Thomson scattering system is based on a Nd:YAG laser operating at the second harmonic and a detection branch featuring a high etendue (f /3) transmission grating spectrometer equipped with an intensified charged coupled device camera. The system is able to measure electron density (ne) and temperature (Te) profiles close to the output of the plasma source and, at a distance of 1.25 m, just in front of a target. The detection system enables to measure 50 spatial channels of about 2 mm each, along a laser chord of 95 mm. By summing a total of 30 laser pulses (0.6 J, 10 Hz), an observational error of 3% in ne and 6% in Te (at ne = 9.4 × 1018 m-3) can be obtained. Single pulse Thomson scattering measurements can be performed with the same accuracy for ne > 2.8 × 1020 m-3. The minimum measurable density and temperature are ne <1 × 1017 m-3 and Te <0.07 eV, respectively. In addition, using the Rayleigh peak, superimposed on the Thomson scattered spectrum, the neutral density (n0) of the plasma can be measured with an accuracy of 25% (at n0 = 1 × 1020 m-3). In this report, the performance of the Thomson scattering system will be shown along with unprecedented accurate Thomson-Rayleigh scattering measurements on a low-temperature argon plasma expansion into a low-pressure background. © 2012 American Institute of Physics.