In order to investigate the Plasma-Focus (PF) pinch dynamics within the large PF-1000 facility the use was made of fast streak-and frame-cameras operated as the routine optical diagnostic tools. They enabled images of a current-sheath (CS) layer and the PF-pinch to be recorded within the visible range (VR) at chosen instants of the investigated PF-discharges. The measurements were carried out end-and side-on the PF-1000 electrode system under different experimental conditions. For the temporal synchronization of both cameras with the chosen phases of the PF discharge, we used current derivative (dI/dt) waveforms and X-ray signals recorded for each shot. During the described PF-1000 experiments, we performed also other complimentary measurements. Particular attention was paid to studies of current-and voltage-waveforms of the investigated discharges, to a comparison of the total neutron yields measured by means of silver activation counters, and to the analysis of time-resolved neutron-and X-ray-signals recorded with several scintillation detectors. Results of the observations carried out with the fast streakand frame-cameras, which were compared with other experimental studies, allowed better understanding of all the PF-discharge phases to be achieved. In particular, the correlation of different quantum-and corpuscular-radiation pulses, which has influence on the total fusion-neutron yield, has been analyzed. 52.58.Lq. 52.59.Hq PACS
Abstract:Plasma research poses a radiation hazard. Due to the program of deuterium plasma research using the PF-1000 device, it is an intensive source of neutrons (up to 10 11 n · −1 ) with energy of 2,45 MeV and ionizing electromagnetic radiation with a broad energy spectrum. Both types of radiation are mostly emitted in ultra-short pulses (∼100 ns). The aim of this work was to test and calibrate the RSS-131 radiometer for its application in measurements of ultra-short electromagnetic radiation pulses with broad energy spectrum emitted during PF-1000 discharge. In addition, the results of raw measurements performed in the control room are presented. 87.55.N, 52.58.Lq PACS (2008):
Presented paper describes the results of the individual doses measurements for ionizing radiation, carried out by the Laboratory of Individual and Environmental Doses Monitoring (PDIS) of the Central Laboratory for Radiological Protection in Warsaw (CLOR) for the medical staff employees in several nuclear medicine (NM) departments across Poland. In total there are48 NM departments in operation in Poland [1] (consultation in Nuclear Atomic Agency). Presented results were collected over the period from January 2011 to December 2011 at eight NM departments located in Krakow, Warszawa (two departments), Rzeszow (two departments), Opole, Przemysl and Gorzow Wielkopolski. For radiation monitoring three kinds of thermo luminescence dosimeters (TLD) were used. The first TLD h collected information about whole body (C) effective dose, the second dosimeter was mounted in the ring (P) meanwhile the third on the wrist (N) of the tested person. Reading of TLDs was performed in quarterly periods. As a good approximation of effective and equivalent dose assessment of operational quantities both the individual dose equivalent Hp(10) and the Hp(0.07) were used. The analysis of the data was performed using two methods The first method was based on quarterly estimations of Hp(10)q and Hp(0.07)q while the second measured cumulative annual doses Hp(10)a and Hp(0.07)a. The highest recorded value of the radiation dose for quarterly assessments reached 24.4 mSv and was recorded by the wrist type dosimeter worn by a worker involved in source preparation procedure. The mean values of Hp(10)q(C type dosimeter) and Hp(0.07)q (P and N type dosimeter) for all monitored departments were respectively 0.46 mSv and 3.29 mSv. There was a strong correlation between the performed job and the value of the received dose. The highest doses always were absorbed by those staff members who were involved in sources preparation. The highest annual cumulative dose for a particular worker in the considered time period was 4.22 mSv for Hp(10)a and 67.7 mSv for Hp(0.07)a. In 2011 no case of exceeding the allowed dose limits was noted.
<p>Biochar (charcoal made from biomass in the pyrolysis process) has found broad application in agriculture. The research performed with biochar revealed the positive impact of biochar application for chemical and physical properties of soil. Biochar was also used as an material for decontamination of soil from heavy metals and pesticides. The improved water retention of soil after biochar application was shown as well. There are particular research concerning the usage of biochar as an material for decontamination of soil from anthropogenic radioactive material including Cs-137 and Sr-90 deposited after nuclear weapon test. However, the biochar find the most practical application in agriculture for improvement of crops efficiency and water retention of soils. The typical application amount of biochar for agricultural purpose varies from 40 to 100 Mg ha<sup>-1</sup>.</p><p>Actually, there are numerous research activities focused on the direct impact of biochar on physical and chemical soil properties. Simultaneously lack of information are available for issue if and how biochar impact for environment radioactivity. As one of that impact could be &#160;the influence on radon emission from soil surface. The aim of presented work was to investigate the impact of biochar application into the soil for the radon emission process.</p><p>The research objects were soil samples collected from experimental fields with biochar applied at doses from 1 to 100 Mg ha<sup>-1</sup>. Two type of biochar were investigated &#8211; first biochar produced from sunflower husk at temperature of 650&#176;C and second biochar produced from wood chips at temperature of 650&#176;C. The radon emanation coefficient were assessed using active cumulative technique incorporating AlphaGUARD instrument equipped with sealed accumulation box.&#160; In addition, we directly measured radon exhalation rate at the experimental fields. As the emanation coefficient calculation require the information on Ra-226 activity concentration, the gamma spectrometry analysis using HPGe detector were performed for samples collected on particular field. &#160;</p><p>The results of activity concentration assessments shown that the most visible effect of biochar application into the soil is associated with the reduction of soil bulk density by this material. No significant changes in activity concentration depending on the biochar dose applied were observed for Ra-226. Fluctuation in radon exhalation rate as well as in emanation coefficient, depending on the biochar dose (from 1 to 100 Mg ha<sup>-1</sup>) were observed and presented.</p><p>The research was partially conducted under the projects &#8220;Water in soil &#8211; satellite monitoring and improving the retention using biochar&#8221; no. BIOSTRATEG3/345940/7/NCBR/2017, which was financed by the Polish National Centre for Research and Development in the framework of &#8220;Environment, agriculture and forestry&#8221; &#8211; BIOSTRATEG strategic R&D programme.</p>
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