Low- and intermediate-beta, 352-MHz superconducting half-wave resonators for high power hadron acceleration

Two prototypes of superconducting, 352 MHz coaxial half-wave resonators with β=0.17 and β=0.31 have been designed, constructed, and tested at INFN-LNL, in the framework of the SPES and EURISOL DS projects. Main features of these double-wall, 2-gap structures are compactness, mechanical stability, and easy installation in different kinds of cryostats. Their acceleration capabilities are similar to the ones of Spoke resonators with similar β. These cavities are being developed for acceleration of high power hadron beams in the 5–100  MeV/u energy range

The non-rfq resonators of the PIAVE linac

The PIAVE superconducting linac is not only made of rfqs; 8 low β superconducting quarter wave resonators, working at 80 MHz, will give an equivalent acceleration voltage of 7.2 MV; a room temperature triple harmonic buncher working at 40 MHz will match the beam to the rfq input and 2 room temperature, 80 MHz rebunchers will match the beam produced by PIAVE into the linac ALPI. The construction and testing of the first superconducting cavity was more than successful: the resonator, at the design power of 7W, reached 6.3 MV/m corresponding to a total acceleration voltage of 1.13 MV at β=0.047. This result allowed us to increase the linac design accelerating field from 3 MV/m to 5 MV/m. The 7 remaining superconducting cavities are presently under construction, and they will be completed within 1998. While the more conventional, room temperature 80 MHz rebunchers are at the design stage, the triple harmonic buncher, made of 2 quarter wave resonators, was constructed, tested and it is ready for installation

Occurrence of ash dieback in stands and plantings

The results of forest pathology investigation carried out in 2014 in ash stands of the republic are analyzed. Incidence of damaged branches is 100%. Occurrence of the disease on the first and second stand stories are 89.9% and 73.3% consequently, and on underbrush is 14.8%. Less disease stability have young plants in forest nurseries, occurrence of the necrosis is 91.6%. The development of ash dieback in forest sites differes insignificantly and increases weakly in South-North line. Average category of tree state 3.3 refers the stands to weakened hard. Ash decline is continued in forests, the number of wind-fallen trees in eight years is up 15.6 to 96.8%. On grows plots of some forestries ash trees fully died in this period. Branch necrosis develops together with Armillaria root rot (correlation coefficient is 0.81). Crone declining is faster than root rot formation, some water sprouts form even on weakened trees. This gives evidence of increasing the intensity of pathogen Hymenoscyphus fraxineus development in Belarus and decreasing the disease stand stability in last 6 years

Ranking of silvicultural areas by the threat of annosum root rot in pine stands

The paper presents a ranking of forest sites according to the threat ofinfection of planting Pinus sylvestrisstands by Heterobasidion annosum.8 degrees of treat of infection are marked out according to the site characteristics and types of habitat and moisture conditions. Presented gradation underlined planning of forest stands with susceptible species, that would allow to make for creation of more stable stands, reduction of infection and decrease costs of protection measures

Efficacy increase of silvicultural measures with biological methods in the pine stands

Based on the analysis of database of the pine stands of Belarus affected by annosum root rot, and the results of longstanding research the substantiati on of silvicultural criteria for designation of stump treatment with biological preparations in the pine fore sts to limit the severity of the pathogen is given. It is proposed to differ site selection for stump treatment according to the regional-typological principle because of significant differences in the relative infestation of pine stands in different forest conditions. It was found that that the treatment should be carried out in pine stands of mossy and bracken series of forest types I–III age classes, and in the pine forest s of Gomel and Mogilev region also in age class IV, as well as heather, lichen and cranberry series of fore st types. In this case, the use of biological agents on the basis of the fungus Phlebiopsis gigantea is useful when conducting selective and complete sanitary felling (regardless of intensity), as well as thi nning and cleaning litter (with a sample of at least 20% of a physiologically live pine wood is cut down from the stock) at steady daily average tempera-tures of at least +5°C