La surveillance phytosanitaire de la forêt en région méditerranéenne

La stratégie de lutte est améliorée par une surveillance permanente dépendant d'un réseau en 3 éléments : observation, technique, administration. L'action des principaux insectes ravageurs et agents pathogènes est évoquée

The Majorana Demonstrator: A Search for Neutrinoless Double-beta Decay of 76Ge

Neutrinoless double-beta (0νββ) decay is a hypothesized process where in some even-even nuclei it might be possible for two neutrons to simultaneously decay into two protons and two electrons without emitting neutrinos. This is possible only if neutrinos are Majorana particles, i.e. fermions that are their own antiparticles. Neutrinos being Majorana particles would explicitly violate lepton number conservation, and might play a role in the matter-antimatter asymmetry in the universe. The observation of neutrinoless double-beta decay would also provide complementary information related to neutrino masses. The Majorana Collaboration is constructing the MAJORANA DEMONSTRATOR, with a total of 40-kg Germanium detectors, to search for the 0νββ decay of 76Ge and to demonstrate a background rate at or below 3 counts/(ROI•t•y) in the 4 keV region of interest (ROI) around the 2039 keV Q-value for 76Ge 0νββ decay. In this paper, we discuss the physics of neutrinoless double beta decay and then focus on the MAJORANA DEMONSTRATOR, including its design and approach to achieve ultra-low backgrounds and the status of the experiment

The Majorana Demonstrator readout electronics system

The Majorana Demonstrator comprises two arrays of high-purity germanium detectors constructed to search for neutrinoless double-beta decay in 76Ge and other physics beyond the Standard Model. Its readout electronics were designed to have low electronic noise, and radioactive backgrounds were minimized by using low-mass components and low-radioactivity materials near the detectors. This paper provides a description of all components of the Majorana Demonstrator readout electronics, spanning the front-end electronics and internal cabling, back-end electronics, digitizer, and power supplies, along with the grounding scheme. The spectroscopic performance achieved with these readout electronics is also demonstrated

The MAJORANA DEMONSTRATOR for 0νββ: Current Status and Future Plans

The MAJORANA DEMONSTRATOR will search for neutrinoless-double-beta decay (0νββ) in 76Ge, while establishing the feasibility of a future tonne-scale germanium-based 0νββ experiment, and performing searches for new physics beyond the Standard Model. The experiment, currently under construction at the Sanford Underground Research Facility in Lead, SD, will consist of a pair of modular high-purity germanium detector arrays housed inside of a compact copper, lead, and polyethylene shield. Through a combination of strict materials qualifications and assay, low-background design, and powerful background rejection techniques, the Demonstrator aims to achieve a background rate in the 0νββ region of interest (ROI) of no more than 3 counts in the 0νββ-decay ROI per tonne of target isotope per year (cnts/(ROI-t-y)). The current status of the Demonstrator is discussed, as are plans for its completion

A Dark Matter Search with MALBEK

The Majorana Demonstrator is an array of natural and enriched high purity germanium detectors that will search for the neutrinoless double-beta decay of 76Ge and perform a search for weakly interacting massive particles (WIMPs) with masses below 10 GeV. As part of the Majorana research and development efforts, we have deployed a modified, low-background broad energy germanium detector at the Kimballton Underground Research Facility. With its sub-keV energy threshold, this detector is sensitive to potential non-Standard Model physics, including interactions with WIMPs. We discuss the backgrounds present in the WIMP region of interest and explore the impact of slow surface event contamination when searching for a WIMP signal

Search for Neutrinoless Double- β Decay in Ge 76 with the Majorana Demonstrator

The Majorana Collaboration is operating an array of high purity Ge detectors to search for neutrinoless double-β decay in Ge76. The Majorana Demonstrator comprises 44.1 kg of Ge detectors (29.7 kg enriched in Ge76) split between two modules contained in a low background shield at the Sanford Underground Research Facility in Lead, South Dakota. Here we present results from data taken during construction, commissioning, and the start of full operations. We achieve unprecedented energy resolution of 2.5 keV FWHM at Qββ and a very low background with no observed candidate events in 9.95 kg yr of enriched Ge exposure, resulting in a lower limit on the half-life of 1.9×1025 yr (90% C.L.). This result constrains the effective Majorana neutrino mass to below 240-520 meV, depending on the matrix elements used. In our experimental configuration with the lowest background, the background is 4.0-2.5+3.1 counts/(FWHM t yr)

Piégeages du chalcographe, Pityogenes chalcographus L. , Coleoptère Scolytide, avec le CME 519-74 et le Chalcoprax.

A summary of projects conducted by the Cemagref on the Pityogenes chalcographus' pheromonal complex is presented with emphasis on the commercial mixture, chalcoprax, as mass attractant. This insect tends to destroy young spruce populations. As with the Phéroprax used for the typographus, this artificial pheromone can be used to monitor the relative fluctuations of the insect populations in time with the barrior type of trap (Roechling) which is far better than the tube model. In addition to a comparative study of their performances, daily permutation indicated a positive effect related to boundary. Thus, by opposition to the Typographus, the number of chalcographus trapped increased when the traps were place a few meters outside the forest boundaries. / Une synthèse des travaux effectués par le CEMAGREF sur le complexe phéromonal du chalcographe est présentée soulignant l'intérêt de la préparation commerciale "Chalcoprax" comme moyen d'attraction de masse de ce scolytide ravageur des jeunes peuplements d'épicéas. Comme avec le "Phéroprax" pour le Typographe , cette phéromone artificielle permet de suivre les fluctuations relatives des populations de l'insecte dans le temps à l'aide de pièges modèle barrière (Roechling) très supérieur au modèle tube. Un essai de permutation journalière de piège,outre l'étude comparative de leur performance, a permis de mettre en évidence un effet position en relation avec la proximité des lisières. Ainsi, à la différence du scolyte liséré ou du typographe, le positionnement des pièges à quelques mètres à l'extérieur des bordures forestières optimise les captures du chalcographe

Un ravageur des plantations et pépinières forestières le hanneton commun, Melolontha melolontha L. : observations biologiques et essais de lutte dans les vergers à graines du CEMAGREF

After damage observed in spruce orchards of the Cemagref in the Lot department (46), biological observations and control tests were conducted in 1989 and 1990 on two populations of cockchafers, Melolontha melolontha L. By monitoring the larval stages, the population dynamics was determined. Two different populations, characterized by flying patterns set-off in time, were demonstrated as well as the co-existence, for a given station, of secondary patterns with a main pattern. Tests conducted on 2 active ingredients and 3 treatment modes have indicated that microgranules of Chlorpyriphos (Dursban 5G) mixed in the soil with a rotavator was effective on young larval stages. The occurrence of natural regulation factors (physical) has been noted. / A la suite de dégats observés dans deux vergers à graines d'épicéa du CEMAGREF dans le Lot (46) des observations biologiques et des essais de lutte ont été effectués en 1989 et 1990 sur 2 population de Hanneton Melolontha melolontha L. Des sondages dans le sol ont permis d'étudier la dynamique de populations par le suivi des stades larvaires. Deux populations différents caractérisées par les "régimes" de vol décalés dans le temps sont mis en évidence ainsi que la coexistence pour une même station de régimes secondaires avec un régime principal. Les essais de 2 matières actives selon 3 modalités de traitement ont souligné l'intérêt du Chlorpyriphos (Dursban 5G) en microgranulés enfouis dans le sol au rotavator lorsqu'il est appliqué sur jeunes stades larvaires. L'incidence des facteurs de régulation naturels (physiques) a été noté

Forêts subnaturelles d'altitude. Observations entomologiques 1994 Cirque des Fonds (74), le Moulinet (06), Bois du Chapitre (05)

The entomofauna of these three forests has been studied in 1994. We have stressed the interest of remarkable species, studied the attack sequences of corticolous pests and wood-eaters on epiceas and firs, and characterized a species by pheromone trapping. The lists of insects on each site are presented by families. / L'entomofaune de ces trois forêts a été étudiée en 1994. On a souligné l'intérêt d'espèces remarquables, étudié les séquences d'attaques des ravageurs sous corticoles et xylophages sur épicéa et sapin et caractérisé une espèce par piégeage avec phéromone. Les listes d'insecte par site sont présentées par familles systématiques