Low-voltage power metal–oxide–semiconductor field-effect transistors (MOSFETs) based on charge compensation using a field plate offer a significant reduction of the area-specific on-resistance. The ...extension of their blocking capability into the so-called medium-voltage range of 150–300 V promises devices with excellent properties being attractive for a wide range of applications. There are two approaches how this voltage-range extension can be realised. Both concepts are linked to different device performance and different development effort. This study discusses both concepts using the example of the 150 V device class and compares the performance gained at the device and application level.
This work presents a review of new concepts and trends to push silicon power MOSFETs beyond their switching boundaries. The multiple issues encountered when increasing switching power loss and slew ...rate are thoroughly explained. Afterwards, a large variety of solutions are proposed in silicon technologies, all of them being experimentally proven and elucidated by physics-based simulations. Among these solutions, co-integrated snubbers, induced avalanche operation, local charge balance, tapered trenches, and cascoded configuration are suggested for low- and high-voltage power MOSFETs.
After 30 years of development, photovoltaic (PV) technology has been recognised to be capable of contributing significantly to future energy supply. The global cumulative installed PV power now ...exceeds 180 GWp, and the annually installed power exceeds 40 GWp. The cost of electrical energy produced by PV systems is now close to that from conventional sources. This study discusses the physics, construction and manufacture of PV cells and modules, taking into account current trends in technology. All parts of PV systems that influence the cost of the electrical energy produced are considered. Three generations of PV module are described. Crystalline silicon (c-Si) is and will remain the dominant PV material at least until 2020 because of its high efficiency, long service time and relatively low cost. It represents nearly 90% of total module production. There are no material supply constraints to limit production and a decrease in c-Si PV module cost to below 0.4 €/Wp before 2017 can be expected. PV power generation will reach industrial grid parity before 2020 and a cumulative installed power of 1 TWp is expected before 2025.
99
m
Tc with a 6 hour half-life is one of the most important medical isotopes used for the Single-Photon Emission Computed Tomography (SPECT) inspection in hospitals of US, Canada, Europe and Japan.
...99
m
Tc isotopes are extracted by the milking method from parent
99
Mo isotopes with a 66 hour half-life. The supply of
99
Mo isotopes now encounters a serious crisis. Hospitals may not suitably receive
99
Mo medical isotopes in near future, due to difficulties in production by research nuclear reactors. Many countries are now looking for alternative ways to generate
99
Mo isotopes other than those with research reactors. We discuss a sustained availability of
99
m
Tc isotopes via the
nat
Mo(γ,
n
) photonuclear reaction, and discuss to solve technical problems for extracting pure
99
m
Tc isotopes from other output materials of photonuclear reactions.
Photoproduction reactions are dominated by isospin rules. In the case of πΔ photoproduction on the proton at forward π angles, the exchange of isospin = 1 meson(π or ρ) in the
t
-channel is the most ...dominant reaction mechanism, which is considered to give a cross section ratio σ(π
+
Δ
0
)/σ(π
−
Δ
++
) of 1/3. The cross section ratio has not been measured precisely experimentally. We present preliminary results for the cross section ratio at E
γ
= 1.5–3.0 GeV. Larger ratios than 1/3 measured by our experiment at LEPS/SPring-8 suggest that the
d̄d
productions are enhanced compared with the
ūu
productions in the photoproduction reactions on the proton.
Combining the spin-dependent dispersion GDH-sum rule, the isotopic-spin-dependent Cabibbo-Radicati sum rule, and the relativistic dipole-moment-fluctuation (i.e. generalized Gottfried) sum rule with ...the three valence quark configuration of nucleons taken into account for the composition of the ground and the excited states of the nucleon, the relevant moments of the distribution and correlation functions of the quark electric dipole moment operators in the nucleon ground state are expressed via the experimentally measurable nucleon resonance photo-excitation amplitudes.These functions are of interest for checking detailed quark-configuration structure of the nucleon state vector. Within the non-relativistic approach to photo-absorption sum rules for the 3N-nuclei a new σ
–1
sum rule proposed which is based on general charge-symmetry (CS) consequences for the “CS-conjugated” triton and
3
He.
The study of polarization effects in reactions with a simplest nucleus, deuteron, plays an important role for the investigation of deuteron structure as well as for the research of the properties of ...the strong interaction. However, data on the tensor observables in the electro- and photoreactions with deuteron appeared not so long ago. We present here a brief overview of the experiments on three such reactions with a deuteron: elastic scattering, photodisintegration and coherent photoproduction of the neutral pion.
The coverage of various issues related to the Russian-Norwegian relations has always been important for the residents of both countries. Opportunities to present new documents and materials, to ...discuss the importance of centuries-old good neighborly relations between Russia and Norway, especially in the North, are not provided often. At the end of April 2018, large-scale scholarly events, devoted specifically to this topic, took place in Nikel and Murmansk. So, a scientific-practical seminar “Russia, Norway and the North. Historical relations” was held in Nikel on April 25 and on the next day in Murmansk the international conference “Neighbors in the Far North: historical ties between Russia and Norway” took place. One of the reasons for these measures was the presentation of the collective monograph “Getting closer: Russia and Norway 1814–1917”. The book was written jointly by Norwegian and Russian historians within the framework of a long-lasting historical megaproject (2008–2015) (led by J.P. Nielsen, AHR, UiT – The Arctic University of Norway). In November 2017 the book was published in Russian in Moscow by the “Ves’ Mir” publishing house after three years of preparation. It is the translation of a monograph, richly illustrated, about the history of Russian-Norwegian relations in the nineteenth and early twentieth centuries, originally published in Norwegian by the Pax Forlag AS, Oslo under the title “Russland kommer nærmere” in 2014.
We discuss main experimental works, where dipole polarizabilities of charged pions have been determined. Possible reasons for the differences between the experimental data are discussed. In ...particular, it is shown that the account of the -meson gives a significant correction to the value of the polarizability obtained in the latest experiment of the COMPASS collaboration.
A novel structure called the shorted-anode super-junction trench clustered insulated gate bipolar transistor (SA-SJ-TCIGBT) is proposed and demonstrated through numerical simulations in 1.2 kV, ...field-stop technology. This device is based on the SJ-TCIGBT concept. In the SA-SJ-TCIGBT structure, due to the introduction of a segmented n+-anode, the device can operate in both forward conducting mode and freewheeling diode mode without any snap back in the current–voltage characteristics. In comparison to the SJ-TCIGBT structure, the proposed device shows significant improvement in trade-off relationship between forward voltage drop and switch off energy losses. Simulation results show that 25% decrease in switching energy losses can be achieved. Moreover, the tail current is effectively reduced without any increase in the overshoot voltage. Detailed two-dimensional modelling of the structure shows that significant amount of excess electrons are extracted through the SA structure during turn-off process.
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