Confinement in electron heated plasmas in Wendelstein 7-X and ASDEX Upgrade; the necessity to control turbulent transport

In electron (cyclotron) heated plasmas, in both ASDEX Upgrade (L-mode) and Wendelstein 7-X, clamping of the ion temperature occurs at Ti ∼ 1.5 keV independent of magnetic configuration. The ions in such plasmas are heated through the energy exchange power as ${n}_{\mathrm{e}}^{2}({T}_{\mathrm{e}}-{T}_{\mathrm{i}})/{T}_{\mathrm{e}}^{3/2}$, which offers a broad ion heating profile, similar to that offered by alpha heating in future thermonuclear fusion reactors. However, the predominant electron heating may put an additional constraint on the ion heat transport, as the ratio Te/Ti > 1 can exacerbates ITG/TEM core turbulence. Therefore, in practical terms the strongly 'stiff' core transport translates into Ti-clamping in electron heated plasmas. Due to this clamping, electron heated L-mode scenarios, with standard gas fueling, in either tokamaks or stellarators may struggle to reach high normalized ion temperature gradients required in a compact fusion reactor. The comparison shows that core heat transport in neoclassically optimized stellarators is driven by the same mechanisms as in tokamaks. The absence of a strong H-mode temperature edge pedestal in stellarators, sofar (which, like in tokamaks, could lift the clamped temperature-gradients in the core), puts a strong requirement on reliable and sustainable core turbulence suppression techniques in stellarators.EC/H2020/633053/EU/Implementation of activities described in the Roadmap to Fusion during Horizon 2020 through a Joint programme of the members of the EUROfusion consortium/Eurato

Effect of vaccination program on immune response, production performance, and carcass composition of Ross 308 broiler chickens

ABSTRACT: The aim of this study was to compare the effect of 2 different vaccination programs using vaccines against infection bronchitis virus (IBV) and avian metapneumovirus (aMPV) on the humoral immune response, production performance, carcass weight and composition, and the percentage of selected internal organs. During the rearing of broiler chickens, blood was collected for serum samples from randomly selected birds from each experimental group on d 1, 21, 28, and 38. Geometric mean titer (GMT) values were determined for the aforementioned diseases using serological ELISA tests, performed during routine veterinary inspections. During rearing, body weight, mortality, and feed consumption were monitored, allowing the calculation of feed consumption per kilogram of body weight gain (FCR) and the European Production Index (EPI). At the end of rearing, 20 chickens were selected for dissection, 10 birds from each group. After slaughter, the weight of the eviscerated carcass was determined, and the percentages of carcass parts and selected internal organs in the body weight were calculated. The vaccination program exerted a significant (P<0.05) effect on body weight on days 14, 21, 28, 35 and 42, the percentage of wings in the carcass and the proportion (%) of heart, liver and spleen in body weight. ELISA showed no significant effect of the vaccination program on the anti-IBV serological response, and no negative effect of covaccination against both diseases on the anti-aMPV serological response

Effect of housing system on carcass composition, meat quality, digestive morphometry, and leg bone dimensions of Ross 308 parent broilers

ABSTRACT: The aim of the present study was to compare the effects of 2 Ross 308 parent broiler housing systems (SLS—slat-litter system vs. LS—litter-based system) in terms of carcass composition, meat quality traits (chemical composition, texture, physicochemical properties), as well as biometric traits of the digestive system and leg bones. The weight of the eviscerated carcass and the proportion of carcass components were determined at the end of the reproductive period (60 wk of life) following slaughter. The lengths and diameters of the individual intestinal segments, the weight of selected internal organs, the acidity (pH24) and electrical conductivity (EC24), as well as the color (L*, a*, b*) of breast and thigh muscles were assessed. The basal chemical composition of the breast and thigh muscles was also determined, texture analysis of the pectoralis major muscle and measurements of the femur and tibia of parent broilers were also carried out. The housing system differentiated the birds in terms of percentage of breast muscle (SLS—27.4% vs. LS—26.0%) and intramuscular fat content in the breast muscle (SLS—1.1% vs. LS—0.7%), spleen weight pH of the breast and thigh muscles and EC of the thigh muscles (SLS—9.3 mS/cm vs. LS—7.0 mS/cm). Differences were also found between the study groups in the color of the breast and thigh muscles. The housing system affected the results of the texture analysis of the pectoralis major muscle. The birds differed significantly (P < 0.05) in terms of gumminess (SLS—11.1 N vs. LS—16.0 N), springiness, chewiness (SLS—17.6 N × cm vs. LS—23.4 N × cm) and cohesiveness parameters. The housing system did not affect the lengths and diameters of the individual intestinal segments, except for the length of the terminal intestine. There was no significant effect of the housing system on the tibia and femur dimensions analyzed. This study provided information about differences in certain carcass characteristics, meat quality, and the digestive system of Ross 308 parent broilers in relation to the maintenance system

Effect of Genotype and Sex on Chemical Composition, Physicochemical Properties, Texture and Microstructure of Spent Broiler Breeder Meat

The aim of this research is to compare the carcass composition and meat quality characteristics of spent Cobb 500 and Ross 308 broiler breeders. A total of 28 carcasses were evaluated—7 female and 7 male carcasses from each genotype. Dissection was performed, and the percentages of neck, wings, skin with subcutaneous fat, abdominal fat, residual components, breast and leg muscles were calculated relative to the eviscerated carcass weight. The breast and leg muscles were evaluated for their chemical composition, color attributes (Lab), acidity (pH24), and electrical conductivity (EC24). Analysis of the structure and texture of the pectoralis major muscle was performed. The genotype of the birds had an impact on the eviscerated carcass weight, percentage of skin with subcutaneous fat, leg muscles, wings, and neck. Broiler breeder genotypes differed in terms of the chemical composition of the breast and leg muscles, except for the water content in the breast muscle and the collagen content in both the breast and leg muscles. The breast muscles of Cobb 500 exhibited lower cooking loss, pH24, redness, and yellowness, while the leg muscles of Ross 308 had lower EC24 but higher cooking loss and lightness values. The pectoralis major muscle of Cobb 500 was firmer and more tender, with a smaller cross-sectional area of the muscle fiber and a smaller vertical (V) diameter of the muscle fiber. Males were characterized by a greater carcass weight and a higher percentage of leg muscles, neck, and carcass remains. On the other hand, females had a higher percentage of breast muscles, skin with subcutaneous fat, and abdominal fat. The sex of the birds affected the chemical composition of the breast and leg muscles, with the exception of the water content in the breast muscles and collagen content in the breast and leg muscles. The breast muscles of females were characterized by higher values of yellowness, although they also exhibited lower pH and cooking loss. In terms of texture analysis of the pectoralis major muscle, the meat of females was characterized by higher tenderness and firmness. However, the analysis of the structure showed that males had a thicker perimysium and endomysium. Regardless of broiler origin and sex, significant differences were found between the breast and leg muscles in terms of the assessed physicochemical features (pH24, EC24, cooking loss), color attributes (Lab) and chemical composition (protein, intramuscular fat, and collagen contents). Genotype and sex interactions were significant for the chemical composition of the breast muscles (protein, fat, collagen) and leg muscles (fat), as well as for the yellow color saturation of the breast muscles and springiness of the pectoralis major muscle. The study produced results that showed the meat and carcasses of spent hens and roosters to be suitable for processing due to their favorable chemical composition, high nutritional value and good technological properties, as assessed based on the results of meat texture and structure

Ablation mass features in multi-pulses femtosecond laser ablate molybdenum target

In this study, the ablation mass features related to reflectivity of bulk Molybdenum (Mo) were investigated by a Ti: Sa 6 fs laser pulse at central wavelength 790 nm. The ablated mass removal was determined using Confocal Microscopy (CM) technique. The surface reflectivity was calibrated and measured by a Lambda 950 spectrophotometer as well as a CCD camera during laser ablation. The ablation mass loss per pulse increase with the increasing of laser shots, meanwhile the surface reflectivity decrease. The multi-pulses (100 shots) ablation threshold of Mo was determined to be 0.15 J/cm2. The incubation coefficient was estimated as 0.835. The reflectivity change of the Mo target surface following multi-pulses laser ablation were studied as a function of laser ablation shots at various laser fluences from 1.07 J/cm2 to 36.23 J/cm2. The results of measured reflectivity indicate that surface reflectivity of Mo target has a significant decline in the first 3-laser pulses at the various fluences. These results are important for developing a quantitative analysis model for laser induced ablation and laser induced breakdown spectroscopy for the first wall diagnosis of EAST tokamak

Characterization of Vanadium Doped 4H- and 6H-SiC Grown by PVT Method Using the Open Seed Backside

score: 13collation: 21-2

Pump–probe capabilities at the SPB/SFX instrument of the European XFEL

Pump–probe experiments at X-ray free-electron laser (XFEL) facilities are a powerful tool for studying dynamics at ultrafast and longer timescales. Observing the dynamics in diverse scientific cases requires optical laser systems with a wide range of wavelength, flexible pulse sequences and different pulse durations, especially in the pump source. Here, the pump–probe instrumentation available for measurements at the Single Particles, Clusters, and Biomolecules and Serial Femtosecond Crystallography (SPB/SFX) instrument of the European XFEL is reported. The temporal and spatial stability of this instrumentation is also presented.Keywords: pump–probe experiments; European XFEL; megahertz pump and probe sources; time-resolved experiments

Performance of tungsten plasma facing components in the stellarator experiment W7-X: Recent results from the first OP2 campaign

The transition to reactor-relevant materials for the plasma facing components (PFCs) is an important and necessary step to provide a proof of principle that the stellarator concept can meet the requirements of a future fusion reactor by demonstrating high performance steady-state operation. As a first step to gain experience with tungsten as plasma-facing material in the Wendelstein 7-X (W7-X) stellarator, graphite tiles coated with an approximately 10 µm MedC tungsten layer (NILPRP Bucharest) were installed to complete the ECRH beam dump area in two of the five plasma vessel modules over an area of approximately one square meter each. In addition, tungsten baffle tiles are installed (40 tiles in total) with either bulk tungsten as part of NBI shine-through target or with a tungsten heavy alloy (W95-Ni3.5-Cu1.5) to replace the graphite tiles that were previously thermally overloaded. Based on an advanced diffusive field line tracing method and EMC3-Eirene simulations, the overloaded baffle tiles were redesigned by making the tiles thinner (i.e. moving the plasma-facing surface (PFS) away from the hot plasma region) and by reducing the local angle of incidence through toroidal displacement of the watershed. Significant erosion of the tungsten tiles can only be expected if sputtering by impurity ions such as carbon or oxygen ions contributes. However, the resulting central concentration of tungsten and the corresponding radiation losses are expected to be marginal. The expected deposition of carbon on the tungsten surfaces in the baffle regions mitigates further the possible tungsten enrichment in the core plasma. In OP2.1, no adverse effects of the installed tungsten PFCs on the plasma performance were observed during normal plasma operation. With the design changes made in the baffle area, the predicted heat load reductions could be experimentally confirmed