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Sample records for avec des muons

  1. Cryptographie quantique avec des états cohérents à longueur d'onde télécom

    NASA Astrophysics Data System (ADS)

    Lodewyck, J.; Tualle-Brouri, R.; Debuisschert, T.; Grangier, P.

    2006-10-01

    Nous proposons un système de distribution quantique de clé avec des variables continues, implémenté avec des technologies télécom à 1550 nm. Le dispositif actuel nous a permis de transmettre une clé secrète brute au taux de 1 Mb/s sur une distance de quelques mètres. Une extension en cours de réalisation nous permettra de transmettre des clés sur des distances allant jusqu'à plusieurs dizaines dekilomètres.

  2. Prediction des vibrations eoliennes d'un systeme conducteur-amortisseur avec une methode temporelle non lineaire

    NASA Astrophysics Data System (ADS)

    Langlois, Sebastien

    Les vibrations eoliennes sont la cause principale de bris de conducteurs en fatigue des lignes aeriennes de transport d'energie electrique. Ces vibrations sont dues a des detachements tourbillonnaires produits dans le sillage du conducteur. Une methode commune de reduction des vibrations est l'ajout d'amortisseurs de vibrations pres des pinces de suspension. Contrairement aux essais en ligne experimentale, la modelisation numerique permet d'evaluer rapidement et a faible cout la performance d'un amortisseur de vibration sur une portee de ligne aerienne. La technologie la plus frequemment utilisee fait appel au principe de balance d'energie (PBE) en evaluant le niveau de vibrations pour lequel la puissance injectee par le vent est egale a la puissance dissipee par le conducteur et l'amortisseur. Les methodes actuelles pour la prediction des vibrations reposent sur des hypotheses simplificatrices quant a la modelisation de l'interaction conducteur-amortisseur. Une approche prometteuse pour la prediction des vibrations est l'utilisation d'un modele numerique temporel non lineaire qui permet de mieux representer la masse, la geometrie, la rigidite et l'amortissement du systeme. L'objectif principal de ce projet de recherche est de developper un modele numerique avec integration temporelle directe d'un conducteur et d'un amortisseur en vibration permettant de reproduire le comportement dynamique du systeme pour la gamme de frequence et d'amplitude typique des vibrations eoliennes des conducteurs. Un modele par elements finis d'un conducteur seul en vibration resolu par integration temporelle directe a d'abord ete developpe en considerant une rigidite de flexion variable. Comme une rigidite de flexion constante et egale a 50% de la rigidite de flexion maximale theorique ( EImax) est jugee adequate pour la modelisation du conducteur, c'est cette valeur qui a ete utilisee pour la suite du projet. Ensuite, des modeles non-lineaires pour deux types d'amortisseur de

  3. Que peut-on voir avec des neutrons? Une introduction pour des non spécialistes

    NASA Astrophysics Data System (ADS)

    Schweizer, J.

    2005-11-01

    Le neutron est une particule élémentaire qui a été découverte en 1932 par James Chadwick. Ses caractéristiques principales sont résumées dans le tableau I. Il a été utilisé pour la première fois par Clifford Shull en 1946 comme outil pour des expériences de diffusion. Cette technique s'est depuis constamment développée pour concerner tous les aspects de la matière condensée: physique, chimie, matériaux, biologie. Il s'agit d'un outil tout à fait exceptionnel car le neutron possède des propriétés uniques et particulièrement adaptées pour ces études.

  4. Les carcinomes epidermoïdes du scrotum: à propos de 7 cas avec revue de la litterature

    PubMed Central

    Halfya, Ayoub; Elmortaji, Khalid; Redouane, Rabii; fethi, Meziane; Rafik, Amine; Mohamed, Ezzoubi; Abdessamad, Chlihi

    2015-01-01

    Quoique rare le carcinome épidermoïde du scrotum a un mauvais pronostic. Les Carcinomes du scrotum induite et - liées au travail sont moins fréquentes en raison d'une meilleure hygiène, vêtements de protection, et la sensibilisation de la cancérogénicité des huiles industrielles. L’épidémie à l'HPV a induit une augmentation de l'incidence. Le traitement de dépend toujours exérèse locale de la lésion primaire. La radiothérapie a peu de bénéfice thérapeutique dans le traitement d'un carcinome épidermoïde du scrotum. La bléomycine peut être utile comme traitement adjuvant pour les maladies ilio-inguinal généralisée avant la tentative exérèse, même si cela n'a pas encore été prouvé. Entre janvier 2011 au 1er janvier 2013, 7 patients atteints de carcinome épidermoïde ont été pris en charge, Trois patients ont présenté une localisation ganglionnaire. Les sept patients ont eu un traitement chirurgical par exérèse large avec reconstruction, Deux patients ont été adressé pour chimiothérapie.2 patients ont présenté une récidive, dont un est décédé. PMID:26113906

  5. Les aspects des frottis cervico-vaginaux chez les femmes vivants avec le VIH suivies à Thiès/Sénégal et association avec le degré d'immunodépression

    PubMed Central

    Bammo, Mariama; Dioussé, Pauline; Thiam, Marietou; Diop, Madoky Maguatte; Berthe, Adama; Faye, Flugence Abdou; Diallo, Thierno Abdoul Aziz; Sarr, Fatou Seck; Dione, Haby; Toure, Papa Souleymane; Diop, Bernard Marcel; Ka, Mamadou Mortalla

    2015-01-01

    De nombreuses études ont démontré que les femmes infectées par le VIH ont un risque accru de survenue de néoplasies cervicales intra épithéliales. L'association entre les deux affections étant bidirectionnelle, l'objectif était de décrire les anomalies cervicales chez les femmes séropositives au virus de l'immunodéficience humaine (VIH), de rechercher des facteurs associés et de proposer des recommandations en termes de suivi de ces femmes. Il s'agissait d'une étude transversale, multicentrique recensant l'ensemble des frottis cervico-vaginaux (FCV) et des colposcopies des patientes infectées par le VIH entre 2012 et 2014 dans les services de dermatologie de Thiès et de Mbour. Les données étaient recueillies et analysées par le logiciel EPI Info 2012 version 3.5.4. Les tests statistiques ont été effectués avec un seuil de significativité p <0,05. Etaient inclus 125 patientes. L’âge moyen était de 38,98 ± 10.2 ans [20-77]. Il n'y avait aucun signe d'appels dans 82.4%. Le FCV était normal dans 32.8%, inflammatoire dans 44.8%. Les anomalies cytologiques concernaient 22,4% dont, ASC-H (suspicion de lésions de haut grade: 2.4%), LSIL (lésions de bas grade: 8.8%), HSIL (lésions de haut grade: 4%). Leur majorité (60.7%) avaient un taux de CD4 < 500 et étaient au stade 3 de l'OMS dans 64.3%; la biopsie montrait une dysplasie sévère chez 37.5% des patientes ayant pu réaliser cet examen. Deux patientes ont bénéficié d'un traitement curatif notamment l'exérèse chirurgicale. La survenue de dysplasies cervicales même précoces semble être associée à un stade avancé de l'infection VIH. Un dépistage et un traitement précoces sont absolument nécessaires. PMID:26834915

  6. Réalisation d'un réseau de pièges annulaires : une première étape vers une porte logique quantique avec des atomes froids

    NASA Astrophysics Data System (ADS)

    Dépret, B.; Verkerk, P.; Hennequin, D.

    2002-06-01

    L'objectif de ce projet est de réaliser une porte logique quantique basée sur l'interaction d'atomes dans deux sites voisins dans un réseau optique très désaccordé. Le principal obstacle rencontré vient du faible taux d'occupation des sites de tels réseaux. Nous proposons ici de mettre en oeuvre un nouveau type de réseaux optiques qui devraient pallier cette limitation. Il s'agit d'un réseau unidimensionnel de pièges annulaires “empilés” avec une période de λ/2. L'utilisation d'axicons conduit à une géométrie adaptée des faisceaux et donne le confinement radial dans les anneaux. Le mouvement azimutal peut également être limité par une force auxiliaire. Le bon taux d'occupation est lié au faible nombre de sites remplis à partir du nuage d'atomes froids initial.

  7. Intérêt de l'inspection visuelle à l'acide acétique et au soluté de Lugol avec colposcope dans le dépistage des lésions du col utérin au Gabon

    PubMed Central

    Mpiga, Édith; Ivanga, Mahinè; Koumakpayi, Ismaël Hervé; Engohan-Aloghe, Corinne; Ankély, Junie Chansi; Belembaogo, Ernest; Meye, Jean-François

    2015-01-01

    Introduction Au Gabon, le dépistage des lésions précancéreuses et cancéreuses du col de l'utérus n'est pas systématique. La vulgarisation de ce dépistage suppose l'utilisation d'un test efficace et adapté aux réalités locales. Méthodes L'objectif de cette étude était de comparer les performances du frottis cervico-vaginal (FCV) conventionnel et de l'inspection visuelle à l'acide acétique (IVA) et au soluté de Lugol (IVL) couplée à la colposcopie, dans la détection des lésions du col utérin au Gabon. Des tests IVA/IVL et FCV ont été effectués chez 309 femmes gabonaises âgées de 18 à 75 ans. Des biopsies ont été réalisées en cas de résultat positif. Résultats 5 cancers épidermoïdes (1,6%) et 4 lésions précancéreuses (1,3%) ont été confirmées par l'histologie. L'IVA/IVL a présenté une meilleure sensibilité (100%) que le FCV (89%). Toutefois, le FCV est apparu plus spécifique (100% versus 92%). Avec une valeur prédictive (VP) négative de 100%, l'IVA/IVL a permis d'exclure avec certitude la présence de cancer du col lorsque le résultat était négatif, contrairement au FCV (92%). L'IVA/IVL et le FCV ont présenté des VP positives respectivement de 90% et 100%. Conclusion Cette étude montre que l'IVA/IVL avec colposcope couplée à l'histologie en cas de résultat positif apparaît plus performante que le FCV. PMID:26893799

  8. Etude comparative des complications liées à l'utilisation du cathéter veineux périphérique avec et sans système clos à bouchon hépariné

    PubMed Central

    Liu, Ying Chun; Seydou, Togo; Sadio, Yéna; Liang, Tu Zheng; Ge, jin

    2015-01-01

    Introduction L'utilisation correcte du système clos à bouchon hépariné sur les cathéters périphériques pendant les perfusions est une pratique courante dans les pays développés et aussi dans plusieurs pays en développement selon un consensus international établi. Nous comparons les résultats de la formation de thrombus et de l'infection liées au cathéter veineux périphérique chez les patients ayant bénéficié de perfusion avec système clos à bouchon hépariné (groupe expérimentale) et ceux qui ont été perfusé sans bouchon hépariné (groupe témoin). Méthodes Nous avons colligé 100 patients hospitalisés pendant la période de Juillet 2014 à Décembre 2014 dans le service d'hospitalisation de chirurgie thoracique de l'hôpital du Mali qui ont été repartis en 2 groupes de 50 patients chacun pour une analyse comparative. L'observation du thrombus dans la lumière du cathéter est effectuée puis enregistré et tous les cathéters ont été repris pour réalisation de culture bactérienne au laboratoire dans les 2 groupes. Résultats Dans le groupe témoin, il existe un thrombus dans la lumière du cathéter dans 36 cas (72%) et l'examen de culture bactérienne était positif dans 90%. Tandis que dans le groupe expérimental on retrouve 3 cas (6%) de thrombose du cathéter et on note une absence de germe dans l'examen bactériologique. Conclusion L'utilisation correcte du système clos à bouchon hépariné lors des perfusions peut réduire et prévenir de façon significative les complications liées au cathéter notamment l'occlusion par thrombus, leur migration et la survenue de l'infection. PMID:26600900

  9. Muon colliders

    SciTech Connect

    Palmer, R.B. |; Sessler, A.; Skrinsky, A.

    1996-01-01

    Muon Colliders have unique technical and physics advantages and disadvantages when compared with both hadron and electron machines. They should thus be regarded as complementary. Parameters are given of 4 TeV and 0.5 TeV high luminosity {micro}{sup +}{micro}{sup {minus}}colliders, and of a 0.5 TeV lower luminosity demonstration machine. We discuss the various systems in such muon colliders, starting from the proton accelerator needed to generate the muons and proceeding through muon cooling, acceleration and storage in a collider ring. Problems of detector background are also discussed.

  10. Muon Collider

    SciTech Connect

    Palmer, R.

    2009-10-19

    Parameters are given of muon colliders with center of mass energies of 1.5 and 3 TeV. Pion production is from protons on a mercury target. Capture, decay, and phase rotation yields bunch trains of both muon signs. Six dimensional cooling reduces the emittances until the trains are merged into single bunches, one of each sign. Further cooling in 6 dimensions is then applied, followed by final transverse cooling in 50 T solenoids. After acceleration the muons enter the collider ring. Ongoing R&D is discussed.

  11. Muon muon collider: Feasibility study

    SciTech Connect

    1996-06-18

    A feasibility study is presented of a 2 + 2 TeV muon collider with a luminosity of L = 10{sup 35} cm{sup {minus}2} s{sup {minus}1}. The resulting design is not optimized for performance, and certainly not for cost; however, it does suffice--the authors believe--to allow them to make a credible case, that a muon collider is a serious possibility for particle physics and, therefore, worthy of R and D support so that the reality of, and interest in, a muon collider can be better assayed. The goal of this support would be to completely assess the physics potential and to evaluate the cost and development of the necessary technology. The muon collider complex consists of components which first produce copious pions, then capture the pions and the resulting muons from their decay; this is followed by an ionization cooling channel to reduce the longitudinal and transverse emittance of the muon beam. The next stage is to accelerate the muons and, finally, inject them into a collider ring which has a small beta function at the colliding point. This is the first attempt at a point design and it will require further study and optimization. Experimental work will be needed to verify the validity of diverse crucial elements in the design.

  12. Prise en charge hospitalière de la malnutrition aigue sévère chez l'enfant avec des préparations locales alternatives aux F-75 et F-100: résultats et défis

    PubMed Central

    Nguefack, Félicitée; Adjahoung, Chritoph Akazong; Keugoung, Basile; Kamgaing, Nelly; Dongmo, Roger

    2015-01-01

    Introduction La mise en œuvre des directives de l'OMS permettrait de réduire significativement la mortalité hospitalière due à la malnutrition sévère. Cependant, elle n'est pas effective et la pénurie en aliments thérapeutiques est l'une des principales causes. L’étude décrit notre expérience sur la prise en charge hospitalière de la malnutrition aigue sévère avec des laits alternatifs aux F75 et F100 composés localement. Méthodes Il s'agissait d'un essai clinique non randomisé. La prise en charge des patients utilisait les laits composés localement et une évaluation quotidienne du gain pondéral était faite. Résultats L’étude a porté sur 41 sujets âgés de 6 à 59 mois. Au total, 73,2% avaient le kwashiorkor-marasmique, 17,0% le kwashiorkor, 9,8% le marasme et 41,5% étaient infectés par le VIH. Nous avons noté une prise progressive du poids d'environ 10 g/kg/jour vers le 7ème jour et de 15 à 20 g/kg/jour en fin d'hospitalisation. Le taux de mortalité était de 21,9% soit une réduction de 8,4% des chiffres antérieurs. Conclusion Malgré les obstacles financiers liés au coût des ingrédients, les préparations lactées alternatives aux standards F75 et F100, sont adaptables dans notre contexte. En l'absence des formules standards de l'OMS et lorsque la référence vers une structure qui en disposent n'est pas possible, les préparations locales permettraient de réhabiliter efficacement les patients. D'autres recherches pointues permettraient de tirer les ingrédients uniquement de notre environnement. Elles contribueraient ainsi à minimiser les couts des préparations et de favoriser la pérennisation des laits thérapeutiques locaux. PMID:26587175

  13. Mesure du taux de la capture radiative du muon par l'hydrogene liquide

    NASA Astrophysics Data System (ADS)

    Jonkmans, Guy

    À basse énergie, l'interaction faible entre leptons et quarks est décrite par une interaction de la forme courant × courant de type V - A. La présence de l'interaction forte induit des couplages additionnels qui doivent être déterminés expérimentalement. De ceux-ci, le couplage pseudoscalaire induit, gp , est mesuré avec la plus grande incertitude et fait l'objet de la présente recherche. L'hypothèse du Courant Axial Partiellement Conservé (CAPC) et l'usage de la relation de Goldberger-Treiman relie gp au couplage axial ga . Cette relation a été vérifiée traditionnellement par la Capture Ordinaire du Muon (COM) à une valeur fixe du moment de transfert q. La Capture Radiative du Muon (CRM), m- p-->nnmg , est un meilleur outil pour l'étude de gp à cause de sa dépendance variable en q2 qui offre une plus grande sensibilité dans la partie à haute énergie du spectre des photons. Toutefois, le petit rapport d'embranchement (~10-8) de la CRM par rapport à la désintégration du muon a retardé cette mesure jusqu'à ce jour. La théorie et les difficultés expérimentales associées à la détection des photons de CRM sont présentées au deuxième chapitre. On décrit ensuite, au troisième chapitre, les composantes du système de détection. Ce détecteur est un spectromètre à paires de grand angle solide (~3p) et qui permet l'observation des photons par l'analyse des électrons et des positrons de photo-conversion. Ainsi, le bruit de fond important des neutrons de la COM ne constitue pas un problème pour cette mesure. Nous décrivons, au quatrième chapitre, toutes les étapes de l'analyse, nécessaires pour la réduction des multiples bruits de fond. Le cinquième chapitre présente le calcul des efficacités ainsi que l'estimation des erreurs systématiques. Le sixième chapitre démontre comment l'on extrait le rapport d'embranchement pour la CRM ainsi que la valeur ae gp . On insiste sur la dépendance de gp en fonction de la valeur de

  14. Muon Muon Collider: Feasibility Study

    SciTech Connect

    Gallardo, J.C.; Palmer, R.B.; Tollestrup, A.V.; Sessler, A.M.; Skrinsky, A.N.; Ankenbrandt, C.; Geer, S.; Griffin, J.; Johnstone, C.; Lebrun, P.; McInturff, A.; Mills, Frederick E.; Mokhov, N.; Moretti, A.; Neuffer, D.; Ng, K.Y.; Noble, R.; Novitski, I.; Popovic, M.; Qian, C.; Van Ginneken, A. /Fermilab /Brookhaven /Wisconsin U., Madison /Tel Aviv U. /Indiana U. /UCLA /LBL, Berkeley /SLAC /Argonne /Sobolev IM, Novosibirsk /UC, Davis /Munich, Tech. U. /Virginia U. /KEK, Tsukuba /DESY /Novosibirsk, IYF /Jefferson Lab /Mississippi U. /SUNY, Stony Brook /MIT /Columbia U. /Fairfield U. /UC, Berkeley

    2012-04-05

    A feasibility study is presented of a 2 + 2 TeV muon collider with a luminosity of L = 10{sup 35} cm{sup -2}s{sup -1}. The resulting design is not optimized for performance, and certainly not for cost; however, it does suffice - we believe - to allow us to make a credible case, that a muon collider is a serious possibility for particle physics and, therefore, worthy of R and D support so that the reality of, and interest in, a muon collider can be better assayed. The goal of this support would be to completely assess the physics potential and to evaluate the cost and development of the necessary technology. The muon collider complex consists of components which first produce copious pions, then capture the pions and the resulting muons from their decay; this is followed by an ionization cooling channel to reduce the longitudinal and transverse emittance of the muon beam. The next stage is to accelerate the muons and, finally, inject them into a collider ring wich has a small beta function at the colliding point. This is the first attempt at a point design and it will require further study and optimization. Experimental work will be needed to verify the validity of diverse crucial elements in the design. Muons because of their large mass compared to an electron, do not produce significant synchrotron radiation. As a result there is negligible beamstrahlung and high energy collisions are not limited by this phenomena. In addition, muons can be accelerated in circular devices which will be considerably smaller than two full-energy linacs as required in an e{sup +} - e{sup -} collider. A hadron collider would require a CM energy 5 to 10 times higher than 4 TeV to have an equivalent energy reach. Since the accelerator size is limited by the strength of bending magnets, the hadron collider for the same physics reach would have to be much larger than the muon collider. In addition, muon collisions should be cleaner than hadron collisions. There are many detailed particle

  15. Contribution à la modélisation du soudage TIG des tôles minces d'acier austénitique 304L par un modèle source bi-elliptique, avec confrontation expérimentale

    NASA Astrophysics Data System (ADS)

    Aissani, M.; Maza, H.; Belkessa, B.; Maamache, B.

    2005-05-01

    Ce travail contribue dans la modélisation du phénomène du soudage de l'acier inoxydable Austénitique 304L, afin d'étudier le comportement thermique d'un joint de soudure, obtenu par le procédé de soudage à l'arc électrique TIG (Tungsten-Inert-Gas). Le modèle simulant la source d'énergie de soudage, utilise une distribution surfacique Gaussienne du flux de chaleur provenant de l'arc électrique. La forme de cette source est supposée circulaire pour un premier cas et de forme bi-elliptique pour un second cas, tout en procédant à l'évaluation des champs et cycles thermiques à chaque instant, pour déterminer l'étendu des zones à risque, et l'effet de la vitesse de soudage sur ces dernières. Permettant ainsi de remonter par la suite, aux problèmes de contraintes résiduelles et déformations générées dans l'assemblage soudé. L'équation de chaleur régissant le problème est discrétisée par la méthode des volumes finis. Les calculs sont effectués en considérant que les propriétés physiques et thermiques ainsi que les conditions aux limites de convection et rayonnement, sont dépendante de la température. Pour évaluer la précision du modèle, une comparaison avec des mesures expérimentales de température d'un essai de soudage a été effectuée, les résultats indiquent un bon accord.

  16. Polarized muon beams for muon collider

    NASA Astrophysics Data System (ADS)

    Skrinsky, A. N.

    1996-11-01

    An option for the production of intense and highly polarized muon beams, suitable for a high-luminosity muon collider, is described briefly. It is based on a multi-channel pion-collection system, narrow-band pion-to-muon decay channels, proper muon spin gymnastics, and ionization cooling to combine all of the muon beams into a single bunch of ultimately low emittance.

  17. Muons in gamma showers

    NASA Technical Reports Server (NTRS)

    Stanev, T.; Vankov, C. P.; Halzen, F.

    1985-01-01

    Muon production in gamma-induced air showers, accounting for all major processes. For muon energies in the GeV region the photoproduction is by far the most important process, while the contribution of micron + micron pair creation is not negligible for TeV muons. The total rate of muons in gamma showers is, however, very low.

  18. Comportement inélastique de l'alliage AlMgSi1 avec prise en compte des effets liés au chargement et à la restauration dépendant du temps

    NASA Astrophysics Data System (ADS)

    Ismar, H.; Penth, M.; Ismar, H.; Penth, M.

    1998-04-01

    In addition to viscous effects, metals show recovery effects especially at elevated temperatures. These effects are opposed to the hardening of the material. Elevated temperature means a temperature T geq 0.4 T_M (T_M is the melting temperature). This limit is partially exceeded in the investigation of AlMgSi1 in a temperature range from T=25 ^circC to T=200 ^circC. The paper presented shows the considered effects and their repercussions on the inelastic behaviour of AlMgSi1. First a viscoplastic modelling based on a transition flow potential (TFP) is illustrated. This modelling is able to describe the phenomenon observed. The basis of the material modelling is the viscoplastic modelling of Chaboche [CITE]. Finally the results of the modelling are compared qualitatively and quantitatively with the experiments. Généralement, les matériaux métalliques présentent, particulièrement à hautes températures, en complément des propriétés visqueuses, des effets de restauration qui s'opposent à l'écrouissage du matériau. Par hautes températures nous entendons une température telle que T geq 0,4 T_M et où T_M est la température de fusion de l'alliage consideré. Pour l'alliage AlMgSi1 cette limite sera partiellement dépassée dans le domaine de température examiné, soit : 25 < T leq 200 ^circC. Ce document présente les incidences de la viscosité associée à la restauration statique sur le comportement inélastique de l'alliage AlMgSi1. On présente un modèle viscoplastique basé sur un potentiel d'écoulement dit de transition (PET) capable de décrire les observations expérimentales reportées. Le point de départ est le modèle viscoplastique de Chaboche [CITE]. Finalement, l'ensemble des résultats expérimentaux sont comparés qualitativement et quantitativement aux prévisions issues du modèle.

  19. Muon Bunch Coalescing

    SciTech Connect

    Johnson, Rolland P; Ankenbrandt, Charles; Bhat, Chandra; Popovic, Milorad; Bogacz, Alex; Derbenev, Yaroslav

    2007-06-25

    The idea of coalescing multiple muon bunches at high energy to enhance the luminosity of a muon collider provides many advantages. It circumvents space-charge, beam loading, and wakefield problems of intense low energy bunches while restoring the synergy between muon colliders and neutrino factories based on muon storage rings. A sampling of initial conceptual design work for a coalescing ring is presented here.

  20. The CMS muon detector

    NASA Astrophysics Data System (ADS)

    Giacomelli, P.

    2002-02-01

    The muon detection system of the Compact Muon Solenoid experiment is described. It consists of three different detector technologies: drift tubes in the barrel region, cathode strip chambers in the endcap region and resistive plate chambers in both barrel and endcap regions. The CMS muon detection system ensures excellent muon detection and efficient triggering in the pseudorapidity range 0< η<2.4. The most recent developments and some results from the R&D program will also be discussed.

  1. Muon beamline at ISIS

    NASA Astrophysics Data System (ADS)

    Eaton, G. H.; Clarke-Gayther, M. A.; Scott, C. A.; Cox, S. F. J.; Kilcoyne, S. H.

    1994-07-01

    The original pulsed surface muon facility was established at the Rutherford Appleton Laboratory's ISIS in 1987. The facility was then upgraded in 1993 from a single beam line and spectrometer to a triple beam facility with three spectrometers working independently. The layout of ISIS is shown. A plan of the ISIS experimental hall is shown, indicating the respective locations of the neutron beams, the KARMEN neutrino facility and the muon beam line complex. Other topics shown in the report include the following: (1) Muon production; (2) Transport of muons to the experimental areas; (3) Positron elimination from the ISIS muon beam; (4) Creation of three independent beam lines.

  2. Muon Catalyzed Fusion

    NASA Technical Reports Server (NTRS)

    Armour, Edward A.G.

    2007-01-01

    Muon catalyzed fusion is a process in which a negatively charged muon combines with two nuclei of isotopes of hydrogen, e.g, a proton and a deuteron or a deuteron and a triton, to form a muonic molecular ion in which the binding is so tight that nuclear fusion occurs. The muon is normally released after fusion has taken place and so can catalyze further fusions. As the muon has a mean lifetime of 2.2 microseconds, this is the maximum period over which a muon can participate in this process. This article gives an outline of the history of muon catalyzed fusion from 1947, when it was first realised that such a process might occur, to the present day. It includes a description of the contribution that Drachrnan has made to the theory of muon catalyzed fusion and the influence this has had on the author's research.

  3. Multiple muons in MACRO

    NASA Technical Reports Server (NTRS)

    Heinz, R.

    1985-01-01

    An analysis of the multiple muon events in the Monopole Astrophysics and Cosmic Ray Observatory detector was conducted to determine the cosmic ray composition. Particular emphasis is placed on the interesting primary cosmic ray energy region above 2000 TeV/nucleus. An extensive study of muon production in cosmic ray showers has been done. Results were used to parameterize the characteristics of muon penetration into the Earth to the location of a detector.

  4. The Muon Detector of Cms

    NASA Astrophysics Data System (ADS)

    Jiang, Chunhua

    2005-04-01

    Muons are an unmistakable signature of most of the LHC physics is designed to explore. The ability to trigger on and reconstruct muons at highest luminorsities is central to the concept of CMS. CMS is characterized by simplicity of design, with one magnet whose solenoideal field facilitates precision racking in the central barrel region and triggering on muons through their bending in the tharnverse and side views. The CMS muon system has three purpose: muon identification, muon trigger and nuon momentum measurement.

  5. Muon and neutrino fluxes

    NASA Technical Reports Server (NTRS)

    Edwards, P. G.; Protheroe, R. J.

    1985-01-01

    The result of a new calculation of the atmospheric muon and neutrino fluxes and the energy spectrum of muon-neutrinos produced in individual extensive air showers (EAS) initiated by proton and gamma-ray primaries is reported. Also explained is the possibility of detecting atmospheric nu sub mu's due to gamma-rays from these sources.

  6. Telecommunication using muon beams

    DOEpatents

    Arnold, Richard C.

    1976-01-01

    Telecommunication is effected by generating a beam of mu mesons or muons, varying a property of the beam at a modulating rate to generate a modulated beam of muons, and detecting the information in the modulated beam at a remote location.

  7. Underwater measurements of muon intensity

    NASA Technical Reports Server (NTRS)

    Fedorov, V. M.; Pustovetov, V. P.; Trubkin, Y. A.; Kirilenkov, A. V.

    1985-01-01

    Experimental measurements of cosmic ray muon intensity deep underwater aimed at determining a muon absorption curve are of considerable interest, as they allow to reproduce independently the muon energy spectrum at sea level. The comparison of the muon absorption curve in sea water with that in rock makes it possible to determine muon energy losses caused by nuclear interactions. The data available on muon absorption in water and that in rock are not equivalent. Underground measurements are numerous and have been carried out down to the depth of approx. 15km w.e., whereas underwater muon intensity have been measured twice and only down to approx. 3km deep.

  8. Muon Collider Progress: Accelerators

    SciTech Connect

    Zisman, Michael S.

    2011-09-10

    A muon collider would be a powerful tool for exploring the energy-frontier with leptons, and would complement the studies now under way at the LHC. Such a device would offer several important benefits. Muons, like electrons, are point particles so the full center-of-mass energy is available for particle production. Moreover, on account of their higher mass, muons give rise to very little synchrotron radiation and produce very little beamstrahlung. The first feature permits the use of a circular collider that can make efficient use of the expensive rf system and whose footprint is compatible with an existing laboratory site. The second feature leads to a relatively narrow energy spread at the collision point. Designing an accelerator complex for a muon collider is a challenging task. Firstly, the muons are produced as a tertiary beam, so a high-power proton beam and a target that can withstand it are needed to provide the required luminosity of ~1 × 10{sup 34} cm{sup –2}s{sup –1}. Secondly, the beam is initially produced with a large 6D phase space, which necessitates a scheme for reducing the muon beam emittance (“cooling”). Finally, the muon has a short lifetime so all beam manipulations must be done very rapidly. The Muon Accelerator Program, led by Fermilab and including a number of U.S. national laboratories and universities, has undertaken design and R&D activities aimed toward the eventual construction of a muon collider. Design features of such a facility and the supporting R&D program are described.

  9. The Muon Collider

    SciTech Connect

    Zisman, Michael S.

    2011-01-05

    We describe the scientific motivation for a new type of accelerator, the muon collider. This accelerator would permit an energy-frontier scientific program and yet would fit on the site of an existing laboratory. Such a device is quite challenging, and requires a substantial R&D program. After describing the ingredients of the facility, the ongoing R&D activities of the Muon Accelerator Program are discussed. A possible U.S. scenario that could lead to a muon collider at Fermilab is briefly mentioned.

  10. Muons and neutrinos

    NASA Technical Reports Server (NTRS)

    Stanev, T.

    1986-01-01

    The first generation of large and precise detectors, some initially dedicated to search for nucleon decay has accumulated significant statistics on neutrinos and high-energy muons. A second generation of even better and bigger detectors are already in operation or in advanced construction stage. The present set of experimental data on muon groups and neutrinos is qualitatively better than several years ago and the expectations for the following years are high. Composition studies with underground muon groups, neutrino detection, and expected extraterrestrial neutrino fluxes are discussed.

  11. Neutrino physics at muon colliders

    SciTech Connect

    King, B.J.

    1998-03-01

    An overview is given of the neutrino physics potential of future muon storage rings that use muon collider technology to produce, accelerate and store large currents of muons. After a general characterization of the neutrino beam and its interactions, some crude quantitative estimates are given for the physics performance of a muon ring neutrino experiment (MURINE) consisting of a high rate, high performance neutrino detector at a 250 GeV muon collider storage ring.

  12. Effets des electrons secondaires sur l'ADN

    NASA Astrophysics Data System (ADS)

    Boudaiffa, Badia

    Les interactions des electrons de basse energie (EBE) representent un element important en sciences des radiations, particulierement, les sequences se produisant immediatement apres l'interaction de la radiation ionisante avec le milieu biologique. Il est bien connu que lorsque ces radiations deposent leur energie dans la cellule, elles produisent un grand nombre d'electrons secondaires (4 x 104/MeV), qui sont crees le long de la trace avec des energies cinetiques initiales bien inferieures a 20 eV. Cependant, il n'y a jamais eu de mesures directes demontrant l'interaction de ces electrons de tres basse energie avec l'ADN, du principalement aux difficultes experimentales imposees par la complexite du milieu biologique. Dans notre laboratoire, les dernieres annees ont ete consacrees a l'etude des phenomenes fondamentaux induits par impact des EBE sur differentes molecules simples (e.g., N2, CO, O2, H2O, NO, C2H 4, C6H6, C2H12) et quelques molecules complexes dans leur phase solide. D'autres travaux effectues recemment sur des bases de l'ADN et des oligonucleotides ont montre que les EBE produisent des bris moleculaires sur les biomolecules. Ces travaux nous ont permis d'elaborer des techniques pour mettre en evidence et comprendre les interactions fondamentales des EBE avec des molecules d'interet biologique, afin d'atteindre notre objectif majeur d'etudier l'effet direct de ces particules sur la molecule d'ADN. Les techniques de sciences des surfaces developpees et utilisees dans les etudes precitees peuvent etre etendues et combinees avec des methodes classiques de biologie pour etudier les dommages de l'ADN induits par l'impact des EBE. Nos experiences ont montre l'efficacite des electrons de 3--20 eV a induire des coupures simple et double brins dans l'ADN. Pour des energies inferieures a 15 eV, ces coupures sont induites par la localisation temporaire d'un electron sur une unite moleculaire de l'ADN, ce qui engendre la formation d'un ion negatif transitoire

  13. Muons in chemistry

    NASA Astrophysics Data System (ADS)

    Clayden, N. J.

    2013-12-01

    Positive muons have long been used as extrinsic probes in chemistry, offering unique properties for the investigation of local magnetism, dynamics, transport and radical kinetics. Exciting new developments in muon beam lines offer the opportunity of extending these studies selectively to surfaces permitting, for example, the detection of increased mobility of polymer chains at the surface of a polymer film. So called pump and probe methods, involving external perturbations by laser irradiation to manipulate vibrational and electronic states, can be followed by muon pulses allowing the probing of the properties of these states. Muoniated radical probes are finding greater use in soft matter. Selectivity is achieved in these complex systems through an appropriate target molecule giving the chance to measure partitioning and interfacial transfer in surfactant systems. Improvements in sample environments allow the observation of muons in increasingly extreme combinations of temperature and pressure, such as supercritical water, allowing the characterization of the chemistry in these systems.

  14. Fast cooling, muon acceleration and the prospect of muon colliders

    NASA Astrophysics Data System (ADS)

    Palmer, Mark

    Facilities based on stored muons offer unique potential for future high-energy physics capabilities. Three key characteristics of the muon make this possible: * The muon is a lepton; * The muon is roughly 200 times as massive as the electron; * The muon decays to an electron and two neutrinos. As the next heavier members of the lepton family with respect to the electron and positron, μ+ and μ-. beams can be collided to provide a precision lepton probe of the electroweak couplings. This makes a muon collider a suitable option for a lepton collider companion to a hadron collider discovery machine...

  15. Contributions a l'etude des lidars a champs visuels multiples

    NASA Astrophysics Data System (ADS)

    Roy, Gilles

    On presente un modele, base sur la diffraction et l'optique geometrique, liant les signaux lidar a champs multiples a la densite de distribution de la taille des particules. On ecrit la relation sous forme matricielle ce qui permet d'obtenir la densite de distribution apparente de la taille des particules par inversion matricielle avec contrainte. On interprete la perturbation causee par la contribution de l'optique geometrique au signal lidar comme de la diffraction causee par une particule de diametre d'environ un micron. La densite de distribution apparente est corrigee a posteriori en calculant la contribution relative des differents ordres de diffusion a l'elargissement de la fonction de phase des particules. La validite du modele est supportee par des simulations Monte Carlo et par des resultats experimentaux obtenus sous des conditions controlees. Finalement, on applique avec succes, la technique d'inversion aux mesures lidar multichamps obtenues sur des nuages.

  16. Fukushima Daiichi Muon Imaging

    NASA Astrophysics Data System (ADS)

    Miyadera, Haruo

    2015-10-01

    Japanese government announced cold-shutdown condition of the reactors at Fukushima Daiichi by the end of 2011, and mid- and long-term roadmap towards decommissioning has been drawn. However, little is known for the conditions of the cores because access to the reactors has been limited by the high radiation environment. The debris removal from the Unit 1 - 3 is planned to start as early as 2020, but the dismantlement is not easy without any realistic information of the damage to the cores, and the locations and amounts of the fuel debris. Soon after the disaster of Fukushima Daiichi, several teams in the US and Japan proposed to apply muon transmission or scattering imagings to provide information of the Fukushima Daiichi reactors without accessing inside the reactor building. GEANT4 modeling studies of Fukushima Daiichi Unit 1 and 2 showed clear superiority of the muon scattering method over conventional transmission method. The scattering method was demonstrated with a research reactor, Toshiba Nuclear Critical Assembly (NCA), where a fuel assembly was imaged with 3-cm resolution. The muon scattering imaging of Fukushima Daiichi was approved as a national project and is aiming at installing muon trackers to Unit 2. A proposed plan includes installation of muon trackers on the 2nd floor (operation floor) of turbine building, and in front of the reactor building. Two 7mx7m detectors were assembled at Toshiba and tested.

  17. Precision muon physics

    NASA Astrophysics Data System (ADS)

    Gorringe, T. P.; Hertzog, D. W.

    2015-09-01

    The muon is playing a unique role in sub-atomic physics. Studies of muon decay both determine the overall strength and establish the chiral structure of weak interactions, as well as setting extraordinary limits on charged-lepton-flavor-violating processes. Measurements of the muon's anomalous magnetic moment offer singular sensitivity to the completeness of the standard model and the predictions of many speculative theories. Spectroscopy of muonium and muonic atoms gives unmatched determinations of fundamental quantities including the magnetic moment ratio μμ /μp, lepton mass ratio mμ /me, and proton charge radius rp. Also, muon capture experiments are exploring elusive features of weak interactions involving nucleons and nuclei. We will review the experimental landscape of contemporary high-precision and high-sensitivity experiments with muons. One focus is the novel methods and ingenious techniques that achieve such precision and sensitivity in recent, present, and planned experiments. Another focus is the uncommonly broad and topical range of questions in atomic, nuclear and particle physics that such experiments explore.

  18. Muon Reconstruction and Identification in CMS

    SciTech Connect

    Everett, A.

    2010-02-10

    We present the design strategies and status of the CMS muon reconstruction and identification identification software. Muon reconstruction and identification is accomplished through a variety of complementary algorithms. The CMS muon reconstruction software is based on a Kalman filter technique and reconstructs muons in the standalone muon system, using information from all three types of muon detectors, and links the resulting muon tracks with tracks reconstructed in the silicon tracker. In addition, a muon identification algorithm has been developed which tries to identify muons with high efficiency while maintaining a low probability of misidentification. The muon identification algorithm is complementary by design to the muon reconstruction algorithm that starts track reconstruction in the muon detectors. The identification algorithm accepts reconstructed tracks from the inner tracker and attempts to quantify the muon compatibility for each track using associated calorimeter and muon detector hit information. The performance status is based on detailed detector simulations as well as initial studies using cosmic muon data.

  19. The LHCb Muon System

    SciTech Connect

    Baldini, W.

    2005-10-12

    In this paper is described the design, the construction and the performances of several Multi Wire Proportional Chamber prototypes built for the LHCb Muon system. In particular we report results for detection efficiency, time resolution, high rate performances and ageing effect measured at the CERN T11 test beam area and at the high irradiation ENEA Casaccia Calliope Facility.

  20. On muon energy spectrum in muon groups underground

    NASA Technical Reports Server (NTRS)

    Bakatanov, V. N.; Chudakov, A. E.; Novoseltsev, Y. F.; Novoseltseva, M. V.; Stenkin, Y. V.

    1985-01-01

    A method is described which was used to measure muon energy spectrum characteristics in muon groups underground using mu-e decays recording. The Baksan Telescope's experimental data on mu-e decays intensity in muon groups of various multiplicities are analyzed. The experimental data indicating very flat spectrum does not however represent the total spectrum in muon groups. Obviously the muon energy spectrum depends strongly on a distance from the group axis. The core attraction effect makes a significant distortion, making the spectrum flatter. After taking this into account and making corrections for this effect the integral total spectrum index in groups has a very small depencence on muon multiplicity and agrees well with expected one: beta=beta (sub expected) = 1.75.

  1. Muon capture for the front end of a muon collider

    SciTech Connect

    Neuffer, D.; Yoshikawa, C.; /MUONS Inc., Batavia

    2011-03-01

    We discuss the design of the muon capture front end for a {mu}{sup +}-{mu}{sup -} Collider. In the front end, a proton bunch on a target creates secondary pions that drift into a capture transport channel, decaying into muons. A sequence of rf cavities forms the resulting muon beams into strings of bunches of differing energies, aligns the bunches to (nearly) equal central energies, and initiates ionization cooling. The muons are then cooled and accelerated to high energy into a storage ring for high-energy high luminosity collisions. Our initial design is based on the somewhat similar front end of the International Design Study (IDS) neutrino factory.

  2. Muon collider progress

    SciTech Connect

    Noble, Robert J. FNAL

    1998-08-01

    Recent progress in the study of muon colliders is presented. An international collaboration consisting of over 100 individuals is involved in calculations and experiments to demonstrate the feasibility of this new type of lepton collider. Theoretical efforts are now concentrated on low-energy colliders in the 100 to 500 GeV center-of-mass energy range. Credible machine designs are emerging for much of a hypothetical complex from proton source to the final collider. Ionization cooling has been the most difficult part of the concept, and more powerful simulation tools are now in place to develop workable schemes. A collaboration proposal for a muon cooling experiment has been presented to the Fermilab Physics Advisory Committee, and a proposal for a targetry and pion collection channel experiment at Brookhaven National Laboratory is in preparation. Initial proton bunching and space-charge compensation experiments at existing hadron facilities have occurred to demonstrate proton driver feasibility.

  3. Muon spin rotation studies

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The bulk of the muon spin rotation research work centered around the development of the muon spin rotation facility at the Alternating Gradient Synchrotron (AGS) of Brookhaven National Laboratory (BNL). The collimation system was both designed and fabricated at Virginia State University. This improved collimation system, plus improvements in detectors and electronics enabled the acquisition of spectra free of background out to 15 microseconds. There were two runs at Brookhaven in 1984, one run was devoted primarily to beam development and the other run allowed several successful experiments to be performed. The effect of uniaxial strain on an Fe(Si) crystal at elevated temperature (360K) was measured and the results are incorporated herein. A complete analysis of Fe pulling data taken earlier is included.

  4. The US Muon Accelerator Program

    SciTech Connect

    Torun, Y.; Kirk, H.; Bross, A.; Geer, Steve; Shiltsev, Vladimir; Zisman, M.; /LBL, Berkeley

    2010-05-01

    An accelerator complex that can produce ultra-intense beams of muons presents many opportunities to explore new physics. A facility of this type is unique in that, in a relatively straightforward way, it can present a physics program that can be staged and thus move forward incrementally, addressing exciting new physics at each step. At the request of the US Department of Energy's Office of High Energy Physics, the Neutrino Factory and Muon Collider Collaboration (NFMCC) and the Fermilab Muon Collider Task Force (MCTF) have recently submitted a proposal to create a Muon Accelerator Program that will have, as a primary goal, to deliver a Design Feasibility Study for an energy-frontier Muon Collider by the end of a 7 year R&D program. This paper presents a description of a Muon Collider facility and gives an overview of the proposal.

  5. Muon cherenkov telescope

    NASA Astrophysics Data System (ADS)

    Malamova, E.; Angelov, I.; Kalapov, I.; Davidkov, K.; Stamenov, J.

    2001-08-01

    : The Muon Cerenkov Telescope is a system of water cerenkov detectors, using the coincidence technique to register cosmic ray muons. It is constructed in order to study the variations of cosmic rays and their correlation with solar activity and processes in the Earth magnetosphere. 1 Basic design of the Muon Cerenkov Telescope The telescope has 18 water cerenkov detectors / 0.25 m2 each /, situated in two parallel planes. / Fig. 1/ Each detector /fig. 2/ consists of a container with dimensions 50x50x12.5 cm made of 3mm thick glass with mirror cover of the outer side. The container is filled with distilled water to 10cm level. A photomultiplier is attached to a transparent circle at the floor of the container and the discriminator is placed in its housing. When a charged particle with energy greater than the threshold energy for cerenkov radiation generation passes the radiator, cerenkov photons are initiated and a part of them reach the PMT cathode after multiple reflections from the mirror sides of the container.

  6. Muon Colliders and Neutrino Factories

    SciTech Connect

    Geer, Steve; /Fermilab

    2009-11-01

    Over the past decade, there has been significant progress in developing the concepts and technologies needed to produce, capture, and accelerate {Omicron}(10{sup 21}) muons per year. These developments have paved the way for a new type of neutrino source (neutrino factory) and a new type of very high energy lepton-antilepton collider (muon collider). This article reviews the motivation, design, and research and development for future neutrino factories and muon colliders.

  7. Muon colliders and neutrino factories

    SciTech Connect

    Geer, S.; /Fermilab

    2010-09-01

    Over the last decade there has been significant progress in developing the concepts and technologies needed to produce, capture and accelerate {Omicron}(10{sup 21}) muons/year. This development prepares the way for a new type of neutrino source (Neutrino Factory) and a new type of very high energy lepton-antilepton collider (Muon Collider). This article reviews the motivation, design and R&D for Neutrino Factories and Muon Colliders.

  8. Muon Colliders and Neutrino Factories *

    NASA Astrophysics Data System (ADS)

    Geer, Steve

    2009-11-01

    Over the past decade, there has been significant progress in developing the concepts and technologies needed to produce, capture, and accelerate O(1021) muons per year. These developments have paved the way for a new type of neutrino source (neutrino factory) and a new type of very high energy lepton-antilepton collider (muon collider). This article reviews the motivation, design, and research and development for future neutrino factories and muon colliders.

  9. Centrales au gaz et Energies renouvelables: comparer des pommes avec des pommes

    SciTech Connect

    Bolinger, Mark; Wiser, Ryan; Golove, William

    2003-10-20

    The fundamental conclusion that we draw from this analysis is that one should not to base itself blindly on forecasts prices of natural gas when one compare contracts at price fixes with producers of renewable energy with contracts at variable prices with promoters power stations with gas. Indeed, forecasts of the prices of gas do not succeed not to enter the associated costs with the covering of the risk, that they are connected to the negative pressure against the cover, with the CAPM, with costs of transaction or with unspecified combination of three. Thus, insofar as price stability to length term is developed, better way of comparing the two choices would be to have recourse to the data on the prices in the long term natural gas, and not with forecasts of the prices. During three last years at least, the use of these prices in the long term would have besides license to correct a methodological error who, obviously, seem to have supported unduly, and of relatively important way, power stations with natural gas compared to their competitors of renewable energies.

  10. From Neutrino Factory to Muon Collider

    SciTech Connect

    Geer, S.; /Fermilab

    2010-01-01

    Both Muon Colliders and Neutrino Factories require a muon source capable of producing and capturing {Omicron}(10{sup 21}) muons/year. This paper reviews the similarities and differences between Neutrino Factory and Muon Collider accelerator complexes, the ongoing R&D needed for a Muon Collider that goes beyond Neutrino Factory R&D, and some thoughts about how a Neutrino Factory on the CERN site might eventually be upgraded to a Muon Collider.

  11. Entrevue avec le Dr Charley Zeanah

    PubMed Central

    2013-01-01

    Le Dr Charles Zeanah est titulaire de la chaire de psychiatrie Mary K. Sellars-Polchow, professeur de pédiatrie clinique et vice-président de la pédopsychiatrie au département de psychiatrie et des sciences du comportement de la faculté de médecine de l’Université Tulane, à la Nouvelle-Orléans. Il est également directeur général de l’institut de la santé mentale des nourrissons et des jeunes enfants de Tulane. Il est récipiendaire de nombreux prix, notamment le prix de prévention Irving Phillips (AACAP), la mention élogieuse présidentielle pour sa recherche et son leadership exceptionnels en santé mentale des nourrissons (American Orthopsychiatric Association), le prix d’excellence clinique Sarah Haley Memorial (International Society for Traumatic Stress Studies), le prix de recherche en pédopsychiatrie Blanche F. Ittelson (APA), et le prix Serge Lebovici Award soulignant les contributions internationales à la santé mentale des nourrissons (World Association for Infant Mental Health). Le Dr Zeanah est fellow distingué de l’AACAP, fellow distingué de l’APA et membre du conseil d’administration de Zero to Three. Il est l’éditeur scientifique de Handbook of Infant Mental Health (3e édition) qui est considéré comme étant le manuel de pointe et la référence de base du domaine de la santé mentale des nourrissons.

  12. Physical applications of muon catalysis: Muon capture in hydrogen

    NASA Astrophysics Data System (ADS)

    Filchenkov, V. V.

    2016-07-01

    Results of theoretical and experimental research on capture of negative muons in hydrogen are reported with an emphasis on the accompanying phenomenon of muon catalysis in hydrogen and subtleties of the experimental method. A conclusion is drawn that precise determination of the capture rate is important for refining the standard model.

  13. Écologie des soins de santé au Canada

    PubMed Central

    Stewart, Moira; Ryan, Bridget

    2015-01-01

    Résumé Objectif Présenter un profil populationnel pancanadien des besoins en soins de santé et de leur utilisation, facile d’accès et permettant des comparaisons entre les provinces et avec d’autres instances internationales. Conception Une comparaison des taux d’utilisation des soins de santé entre les provinces en utilisant des données d’enquêtes et des renseignements administratifs sur la santé. Contexte Les provinces du Canada. Principaux paramètres à l’étude Les taux canadiens et provinciaux de personnes en mauvaise santé (présence de problèmes chroniques) et d’utilisation des soins de santé (contacts avec des médecins de famille, avec d’autres médecins spécialistes, avec des infirmières et hospitalisations) sous forme de proportions mensuelles par 1000 habitants normalisées en fonction de l’âge et du genre. Résultats La proportion mensuelle par 1000 habitants de personnes souffrant d’au moins 1 problème chronique variait de 524 au Québec à 638 en Nouvelle-Écosse; les contacts avec un médecin de famille se situaient entre 158 au Québec et 295 en Colombie-Britannique; les contacts avec d’autres médecins spécialistes variaient entre 53 en Saskatchewan et 79 en Ontario; et le nombre de contacts avec des infirmières se situait entre 23 en Colombie-Britannique et 41 au Québec. Le nombre de séjours à l’hôpital variait entre 8 et 11 par 1000 habitants et les proportions étaient semblables d’une province à l’autre. Conclusion Il est essentiel de reconnaître les distinctions entre les provinces pour éclairer les politiques sur la santé dans l’ensemble du pays. Les différences persistaient lorsque les taux étaient normalisés en fonction de la composition démographique variable selon l’âge et le genre dans les provinces. Cet article présente une méthodologie simple à l’aide de données publiquement accessibles qui peut servir dans chaque province à examiner, à l’avenir, l

  14. Muon Spin Rotation Spectroscopy - Utilizing Muons in Solid State Physics

    SciTech Connect

    Suter, Andreas

    2012-10-17

    Over the past decades muon spin rotation techniques (mSR) have established themselves as an invaluable tool to study a variety of static and dynamic phenomena in bulk solid state physics and chemistry. Common to all these approaches is that the muon is utilized as a spin microprobe and/or hydrogen-like probe, implanted in the material under investigation. Recent developments extend the range of application to near surface phenomena, thin film and super-lattice studies. After briefly summarizing the production of so called surface muons used for bulk studies, and discussing the principle differences between pulsed and continuous muon beams, the production of keV-energy muon sources will be discussed. A few topical examples from different active research fields will be presented to demonstrate the power of these techniques.

  15. Electron-Muon Ranger: Performance in the MICE muon beam

    DOE PAGESBeta

    Adams, D.

    2015-12-16

    The Muon Ionization Cooling Experiment (MICE) will perform a detailed study of ionization cooling to evaluate the feasibility of the technique. To carry out this program, MICE requires an efficient particle-identification (PID) system to identify muons. The Electron-Muon Ranger (EMR) is a fully-active tracking-calorimeter that forms part of the PID system and tags muons that traverse the cooling channel without decaying. The detector is capable of identifying electrons with an efficiency of 98.6%, providing a purity for the MICE beam that exceeds 99.8%. Lastly, the EMR also proved to be a powerful tool for the reconstruction of muon momenta inmore » the range 100–280 MeV/c.« less

  16. Electron-Muon Ranger: Performance in the MICE muon beam

    SciTech Connect

    Adams, D.

    2015-12-16

    The Muon Ionization Cooling Experiment (MICE) will perform a detailed study of ionization cooling to evaluate the feasibility of the technique. To carry out this program, MICE requires an efficient particle-identification (PID) system to identify muons. The Electron-Muon Ranger (EMR) is a fully-active tracking-calorimeter that forms part of the PID system and tags muons that traverse the cooling channel without decaying. The detector is capable of identifying electrons with an efficiency of 98.6%, providing a purity for the MICE beam that exceeds 99.8%. Lastly, the EMR also proved to be a powerful tool for the reconstruction of muon momenta in the range 100–280 MeV/c.

  17. An intense low energy muon source for the muon collider

    SciTech Connect

    Taqqu, D.

    1996-05-01

    A scheme for obtaining an intense source of low energy muons is described. It is based on the production of pions in a high field magnetic bottle trap. By ensuring efficient slowing down and extraction of the decay muons an intense intermediate energy muon beam is obtained. For the specific case of negative muons a novel technique called frictional accumulation provides efficient conversion into a 10 keV{mu}{sup {minus}} beam whose emittance is then reduced in a configuration providing extended frictional cooling. The result is a beam of very small transverse and longitudinal emittance that can be used together with an equivalent {mu}{sup +} beam as compact intense muon source for the {mu}{sup +}{mu}{sup {minus}} collider. A final luminosity around 10{sup 34} cm{sup {minus}2}s{sup {minus}1} is expected to be obtained at 2 TeV. {copyright} {ital 1996 American Institute of Physics.}

  18. Electron-muon ranger: performance in the MICE muon beam

    NASA Astrophysics Data System (ADS)

    Adams, D.; Alekou, A.; Apollonio, M.; Asfandiyarov, R.; Barber, G.; Barclay, P.; de Bari, A.; Bayes, R.; Bayliss, V.; Bene, P.; Bertoni, R.; Blackmore, V. J.; Blondel, A.; Blot, S.; Bogomilov, M.; Bonesini, M.; Booth, C. N.; Bowring, D.; Boyd, S.; Bradshaw, T. W.; Bravar, U.; Bross, A. D.; Cadoux, F.; Capponi, M.; Carlisle, T.; Cecchet, G.; Charnley, C.; Chignoli, F.; Cline, D.; Cobb, J. H.; Colling, G.; Collomb, N.; Coney, L.; Cooke, P.; Courthold, M.; Cremaldi, L. M.; Debieux, S.; DeMello, A.; Dick, A.; Dobbs, A.; Dornan, P.; Drielsma, F.; Filthaut, F.; Fitzpatrick, T.; Franchini, P.; Francis, V.; Fry, L.; Gallagher, A.; Gamet, R.; Gardener, R.; Gourlay, S.; Grant, A.; Graulich, J. S.; Greis, J.; Griffiths, S.; Hanlet, P.; Hansen, O. M.; Hanson, G. G.; Hart, T. L.; Hartnett, T.; Hayler, T.; Heidt, C.; Hills, M.; Hodgson, P.; Hunt, C.; Husi, C.; Iaciofano, A.; Ishimoto, S.; Kafka, G.; Kaplan, D. M.; Karadzhov, Y.; Kim, Y. K.; Kuno, Y.; Kyberd, P.; Lagrange, J.-B.; Langlands, J.; Lau, W.; Leonova, M.; Li, D.; Lintern, A.; Littlefield, M.; Long, K.; Luo, T.; Macwaters, C.; Martlew, B.; Martyniak, J.; Masciocchi, F.; Mazza, R.; Middleton, S.; Moretti, A.; Moss, A.; Muir, A.; Mullacrane, I.; Nebrensky, J. J.; Neuffer, D.; Nichols, A.; Nicholson, R.; Nicola, L.; Noah Messomo, E.; Nugent, J. C.; Oates, A.; Onel, Y.; Orestano, D.; Overton, E.; Owens, P.; Palladino, V.; Pasternak, J.; Pastore, F.; Pidcott, C.; Popovic, M.; Preece, R.; Prestemon, S.; Rajaram, D.; Ramberger, S.; Rayner, M. A.; Ricciardi, S.; Roberts, T. J.; Robinson, M.; Rogers, C.; Ronald, K.; Rothenfusser, K.; Rubinov, P.; Rucinski, P.; Sakamato, H.; Sanders, D. A.; Sandström, R.; Santos, E.; Savidge, T.; Smith, P. J.; Snopok, P.; Soler, F. J. P.; Speirs, D.; Stanley, T.; Stokes, G.; Summers, D. J.; Tarrant, J.; Taylor, I.; Tortora, L.; Torun, Y.; Tsenov, R.; Tunnell, C. D.; Uchida, M. A.; Vankova-Kirilova, G.; Virostek, S.; Vretenar, M.; Warburton, P.; Watson, S.; White, C.; Whyte, C. G.; Wilson, A.; Wisting, H.; Yang, X.; Young, A.; Zisman, M.

    2015-12-01

    The Muon Ionization Cooling Experiment (MICE) will perform a detailed study of ionization cooling to evaluate the feasibility of the technique. To carry out this program, MICE requires an efficient particle-identification (PID) system to identify muons. The Electron-Muon Ranger (EMR) is a fully-active tracking-calorimeter that forms part of the PID system and tags muons that traverse the cooling channel without decaying. The detector is capable of identifying electrons with an efficiency of 98.6%, providing a purity for the MICE beam that exceeds 99.8%. The EMR also proved to be a powerful tool for the reconstruction of muon momenta in the range 100-280 MeV/c.

  19. Le syndrome des brides amniotiques et ses difficultés diagnostiques et de prise en charge au Burkina Faso

    PubMed Central

    Nagalo, Kisito; Badiel, Roger; Kouéta, Fla; Tall, François Housséini; Yé, Diarra

    2015-01-01

    Le syndrome des brides amniotiques est une embryo-foetopathie rare, d’étiopathogénie encore inconnue, caractérisé par des malformations crânio-faciales, thoraco-abdominales, des membres et des extrémités. Afin de discuter des difficultés diagnostiques et thérapeutiques du syndrome des brides amniotiques, nous rapportons cinq cas de ce syndrome. Ces cas représentaient autant de phénotypes de la maladie mais avec quelques singularités. Les deux premiers étaient des cas de maladie des brides amniotiques caractérisés l'un par une amputation d'un membre inférieur associée à des lésions cutanées et à une surdité, l'autre par des strictions avec amputation des doigts associées à une fente labio-palatine, une cataracte congénitale et un strabisme. Les trois autres cas correspondaient à des formes létales du Limb Body Wall Complex dont deux avec attache placento-crânienne et un avec attache placento-abdominale. Le renforcement du diagnostic anténatal, l'instauration du conseil génétique et la mise en place d'un registre national des malformations devraient permettre d'améliorer la prise en charge des cas du syndrome des brides amniotiques. PMID:26113939

  20. Nouvelle methode pour les etudes des interactions aeroservoelastiques en boucle ouverte sur les avions F/A-18, CL-604 et ATM et en boucle fermee sur l'ATM

    NASA Astrophysics Data System (ADS)

    Dinu, Alin Dorian

    2006-04-01

    Nous avons concu, implemente puis valide une nouvelle methode d'approximation des forces aerodynamiques non stationnaires a l'aide des polynomes orthogonaux de Chebyshev. Cela represente une contribution originale dans l'analyse des interactions aeroservoelastiques. La premiere serie de resultats obtenus par cette nouvelle methode (erreurs d'approximation des forces aerodynamiques non stationnaires) est comparee avec les resultats des methodes LS et de Pade. La deuxieme serie de resultats (vitesses et frequences de battement obtenues avec cette nouvelle methode) est comparee avec celles obtenues par les methodes classiques LS et de Pade. Ces deux series de resultats obtenus par notre methode et par les deux methodes classiques LS et de Pade sont validees sur trois types differents d'avions: l'ATM (Aircraft Test Model), le F/A-18 en collaboration avec les laboratoires de la NASA Dryden Flight Research Center, et enfin le Challenger CL-604 de Bombardier Aeronautique.

  1. Les astronomes européens auscultent les cieux avec le plus grand télescope du monde

    NASA Astrophysics Data System (ADS)

    Malbet, F.

    2008-09-01

    À l'heure des projets de télescopes extrêmement grands, l'Europe a déjà une longueur d'avance. Le télescope européen (VLT), en mode interférométrique avec l'instrument AMBER devient le plus grand télescope jamais utilisé dans le domaine optique aussi bien en surface de miroir (plus de 150 m2) qúen finesse de résolution qui atteint celle d'un télescope de 130 m de diamètre. Le journal professionnel Astronomy & Astrophysics a publié en 2007 un numéro spécial qui rapporte les premiers résultats obtenus avec l'instrument AMBER (Astronomical MultiBEam Recombiner) par le très grand télescope européen. Ces articles couvrent pratiquement tous les stades de l'évolution stellaire depuis la formation des étoiles et des planètes jusqu'a l'observation de l'explosion de type nova dans un système stellaire évolué. Ces résultats inédits ont été obtenus en utilisant simultanément 3 des 4 télescopes du VLT basés à l'Observatoire européen austral du mont Paranal au Chili. L'instrument AMBER équipant le VLTI (mode interférométrique du VLT) permet dâatteindre une résolution angulaire inégalée de l'ordre du millième de seconde d'angle autorisant l'observation des astres dans différentes longueurs d'onde, dans l'infrarouge proche. Les astronomes obtiennent donc des observations avec une finesse 13 fois plus importante que celle d'un télescope seul. Il devient alors possible de sonder les régions de formation de planètes, d'observer les vents des étoiles en rotation très rapide, d'étudier les différents types de matières éjectées par une étoile massive, de séparer les deux composantes d'une étoile double serrée et de voir en direct l'évolution d'une nova quelques jours seulement après son explosion.

  2. Muon Cooling—emittance exchange

    NASA Astrophysics Data System (ADS)

    Parsa, Zohreh

    2001-05-01

    Muon Cooling is the key factor in building of a Muon collider, (to a less degree) Muon storage ring, and a Neutrino Factory. Muon colliders potential to provide a probe for fundamental particle physics is very interesting, but may take a considerable time to realize, as much more work and study is needed. Utilizing high intensity Muon sources-Neutrino Factories, and other intermediate steps are very important and will greatly expand our abilities and confidence in the credibility of high energy muon colliders. To obtain the needed collider luminosity, the phase-space volume must be greatly reduced within the muon life time. The Ionization cooling is the preferred method used to compress the phase space and reduce the emittance to obtain high luminosity muon beams. We note that, the ionization losses results not only in damping, but also heating. The use of alternating solenoid lattices has been proposed, where the emittance are large. We present an overview of the cooling and discuss formalism, solenoid magnets and some beam dynamics.

  3. High luminosity muon collider design

    SciTech Connect

    Palmer, R.; Gallardo, J.

    1996-10-01

    Muon Colliders have unique technical and physics advantages and disadvantages when compared with both hadron and electron machines. They should be regarded as complementary. Parameters are given of 4 TeV high luminosity {mu}{sup +}{mu}{sup {minus}} collider, and of a 0.5 TeV lower luminosity demonstration machine. We discuss the various systems in such muon colliders.

  4. Muon collider design

    SciTech Connect

    Palmer, R. |; Sessler, A.; Skrinsky, A.

    1996-03-01

    The possibility of muon colliders was introduced by Skrinsky et al., Neuffer, and others. More recently, several workshops and collaboration meetings have greatly increased the level of discussion. In this paper we present scenarios for 4 TeV and 0.5 TeV colliders based on an optimally designed proton source, and for a lower luminosity 0.5 TeV demonstration based on an upgraded version of the AGS. It is assumed that a demonstration version based on upgrades of the FERMILAB machines would also be possible. 53 refs., 25 figs., 8 tabs.

  5. MUON STORAGE RINGS - NEUTRINO FACTORIES

    SciTech Connect

    PARSA,Z.

    2000-05-30

    The concept of a muon storage ring based Neutrino Source (Neutrino Factory) has sparked considerable interest in the High Energy Physics community. Besides providing a first phase of a muon collider facility, it would generate more intense and well collimated neutrino beams than currently available. The BNL-AGS or some other proton driver would provide an intense proton beam that hits a target, produces pions that decay into muons. The muons must be cooled, accelerated and injected into a storage ring with a long straight section where they decay. The decays occurring in the straight sections of the ring would generate neutrino beams that could be directed to detectors located thousands of kilometers away, allowing studies of neutrino oscillations with precisions not currently accessible. For example, with the neutrino source at BNL, detectors at Soudan, Minnesota (1,715 km), and Gran Sasso, Italy (6,527 km) become very interesting possibilities. The feasibility of constructing and operating such a muon-storage-ring based Neutrino-Factory, including geotechnical questions related to building non-planar storage rings (e.g. at 8{degree} angle for BNL-Soudan, and 3{degree} angle for BNL-Gran Sasso) along with the design of the muon capture, cooling, acceleration, and storage ring for such a facility is being explored by the growing Neutrino Factory and Muon Collider Collaboration (NFMCC). The authors present overview of Neutrino Factory concept based on a muon storage ring, its components, physics opportunities, possible upgrade to a full muon collider, latest simulations of front-end, and a new bowtie-muon storage ring design.

  6. Muon tracking underground

    NASA Astrophysics Data System (ADS)

    Battistoni, G.; Campana, P.; Chiarella, V.; Denni, U.; Iarocci, E.

    1986-04-01

    The design and performance of plastic streamer tubes for use in large underground particle-physics experiments such as the muon, astrophysics, and cosmic-ray observatory (MACRO) being developed for Gran Sasso Laboratory are reported. The large (1000 sq m or more) detector area required to achieve high-angular-resolution muon tracking in MACRO is covered by modules with eight 3 x 3-cm-cross section active streamer-tube cells each, similar to those used in the Mt. Blanc Laboratory detector. The MACRO modules have a maximum length of 12 m; and the cells have 60-micron-diameter wires, two conducting graphite sides, and two insulating sides (electrodeless electric-field shaping). The results of performance tests flowing 3:1 He:n-pentane through a tube module are presented graphically. Spatial resolution 1 cm and time resolution 100 ns are obtained, and the ability of the streamer tubes to detect large ionization losses with respect to the minimum is demonstrated.

  7. Research and Development of Future Muon Collider

    SciTech Connect

    Yonehara, K.; /Fermilab

    2012-05-01

    Muon collider is a considerable candidate of the next generation high-energy lepton collider machine. A novel accelerator technology must be developed to overcome several intrinsic issues of muon acceleration. Recent research and development of critical beam elements for a muon accelerator, especially muon beam phase space ionization cooling channel, are reviewed in this paper.

  8. Quasi-isochronous Muon Collection Channels

    SciTech Connect

    Yoshikawa, C.; Ankenbrandt, C.; Neuffer, D.; /Fermilab

    2010-05-01

    Intense muon beams have many potential applications, including neutrino factories and muon colliders. However, muons are produced as tertiary beams, resulting in diffuse phase space distributions. To make useful beams, the muons must be rapidly cooled before they decay. An idea conceived recently for the collection and cooling of muon beams, namely, the use of a Quasi-Isochronous Helical Channel (QIHC) to facilitate capture of muons into RF buckets, has been developed further. The resulting distribution could be cooled quickly and coalesced into a single bunch to optimize the luminosity of a muon collider. After a brief elaboration of the QIHC concept, recent developments are described.

  9. Probing beyond the Standard Model with Muons

    SciTech Connect

    Hisano, Junji

    2008-02-21

    Muon's Properties are the most precisely studied among unstable particles. After discovery of muons in 40's, the studies of muons contributed to construction and establishment of the standard model in the particle physics. Now we are going to LHC era, however, precision frontier is still important in the particle physics. In this article, we review roles of muon physics in the particle physics. Muon g-2, lepton flavor violation (LFV) in muon decay, and electric dipole moment (EDM) of muon are mainly discussed.

  10. The Gran Sasso muon puzzle

    SciTech Connect

    Fernandez-Martinez, Enrique; Mahbubani, Rakhi E-mail: rakhi@cern.ch

    2012-07-01

    We carry out a time-series analysis of the combined data from three experiments measuring the cosmic muon flux at the Gran Sasso laboratory, at a depth of 3800 m.w.e. These data, taken by the MACRO, LVD and Borexino experiments, span a period of over 20 years, and correspond to muons with a threshold energy, at sea level, of around 1.3 TeV. We compare the best-fit period and phase of the full muon data set with the combined DAMA/NaI and DAMA/LIBRA data, which spans the same time period, as a test of the hypothesis that the cosmic ray muon flux is responsible for the annual modulation detected by DAMA. We find in the muon data a large-amplitude fluctuation with a period of around one year, and a phase that is incompatible with that of the DAMA modulation at 5.2σ. Aside from this annual variation, the muon data also contains a further significant modulation with a period between 10 and 11 years and a power well above the 99.9% C.L threshold for noise, whose phase corresponds well with the solar cycle: a surprising observation for such high energy muons. We do not see this same period in the stratospheric temperature data.

  11. Muon Simulation at the Daya Bay SIte

    SciTech Connect

    Mengyun, Guan; Jun, Cao; Changgen, Yang; Yaxuan, Sun; Luk, Kam-Biu

    2006-05-23

    With a pretty good-resolution mountain profile, we simulated the underground muon background at the Daya Bay site. To get the sea-level muon flux parameterization, a modification to the standard Gaisser's formula was introduced according to the world muon data. MUSIC code was used to transport muon through the mountain rock. To deploy the simulation, first we generate a statistic sample of sea-level muon events according to the sea-level muon flux distribution formula; then calculate the slant depth of muon passing through the mountain using an interpolation method based on the digitized data of the mountain; finally transport muons through rock to get underground muon sample, from which we can get results of muon flux, mean energy, energy distribution and angular distribution.

  12. Muon Collider Task Force Report

    SciTech Connect

    Ankenbrandt, C.; Alexahin, Y.; Balbekov, V.; Barzi, E.; Bhat, C.; Broemmelsiek, D.; Bross, A.; Burov, A.; Drozhdin, A.; Finley, D.; Geer, S.; /Fermilab /Argonne /Brookhaven /Jefferson Lab /LBL, Berkeley /MUONS Inc., Batavia /UCLA /UC, Riverside /Mississippi U.

    2007-12-01

    Muon Colliders offer a possible long term path to lepton-lepton collisions at center-of-mass energies {radical}s {ge} 1 TeV. In October 2006 the Muon Collider Task Force (MCTF) proposed a program of advanced accelerator R&D aimed at developing the Muon Collider concept. The proposed R&D program was motivated by progress on Muon Collider design in general, and in particular, by new ideas that have emerged on muon cooling channel design. The scope of the proposed MCTF R&D program includes muon collider design studies, helical cooling channel design and simulation, high temperature superconducting solenoid studies, an experimental program using beams to test cooling channel RF cavities and a 6D cooling demonstration channel. The first year of MCTF activities are summarized in this report together with a brief description of the anticipated FY08 R&D activities. In its first year the MCTF has made progress on (1) Muon Collider ring studies, (2) 6D cooling channel design and simulation studies with an emphasis on the HCC scheme, (3) beam preparations for the first HPRF cavity beam test, (4) preparations for an HCC four-coil test, (5) further development of the MANX experiment ideas and studies of the muon beam possibilities at Fermilab, (6) studies of how to integrate RF into an HCC in preparation for a component development program, and (7) HTS conductor and magnet studies to prepare for an evaluation of the prospects for of an HTS high-field solenoid build for a muon cooling channel.

  13. Vecteurs Singuliers des Theories des Champs Conformes Minimales

    NASA Astrophysics Data System (ADS)

    Benoit, Louis

    En 1984 Belavin, Polyakov et Zamolodchikov revolutionnent la theorie des champs en explicitant une nouvelle gamme de theories, les theories quantiques des champs bidimensionnelles invariantes sous les transformations conformes. L'algebre des transformations conformes de l'espace-temps presente une caracteristique remarquable: en deux dimensions elle possede un nombre infini de generateurs. Cette propriete impose de telles conditions aux fonctions de correlations qu'il est possible de les evaluer sans aucune approximation. Les champs des theories conformes appartiennent a des representations de plus haut poids de l'algebre de Virasoro, une extension centrale de l'algebre conforme du plan. Ces representations sont etiquetees par h, le poids conforme de leur vecteur de plus haut poids, et par la charge centrale c, le facteur de l'extension centrale, commune a toutes les representations d'une meme theorie. Les theories conformes minimales sont constituees d'un nombre fini de representations. Parmi celles-ci se trouvent des theories unitaires dont les representation forment la serie discrete de l'algebre de Virasoro; leur poids h a la forme h_{p,q}(m)=[ (p(m+1) -qm)^2-1] (4m(m+1)), ou p,q et m sont des entiers positifs et p+q<= m+1. L'entier m parametrise la charge centrale: c(m)=1 -{6over m(m+1)} avec n>= 2. Ces representations possedent un sous-espace invariant engendre par deux sous-representations avec h_1=h_{p,q} + pq et h_2=h_{p,q} + (m-p)(m+1-q) dont chacun des vecteurs de plus haut poids portent le nom de vecteur singulier et sont notes respectivement |Psi _{p,q}> et |Psi_{m-p,m+1-q}>. . Les theories super-conformes sont une version super-symetrique des theories conformes. Leurs champs appartiennent a des representation de plus haut poids de l'algebre de Neveu-Schwarz, une des deux extensions super -symetriques de l'algebre de Virasoro. Les theories super -conformes minimales possedent la meme structure que les theories conformes minimales. Les representations

  14. Laser-Assisted Muon Decay

    SciTech Connect

    Liu Aihua; Li Shumin; Berakdar, Jamal

    2007-06-22

    We show theoretically that the muon lifetime can be changed dramatically by embedding the decaying muon in a strong linearly polarized laser field. Evaluating the S-matrix elements taking all electronic multiphoton processes into account we find that a CO{sub 2} laser with an electric field amplitude of 10{sup 6} V cm{sup -1} results in an order of magnitude shorter lifetime of the muon. We also analyze the dependencies of the decay rate on the laser frequency and intensity.

  15. Measurement of muon intensity by Cerenkov method

    NASA Technical Reports Server (NTRS)

    Liu, Z. H.; Li, G. J.; Bai, G. Z.; Liu, J. G.; Geng, Q. X.; Ling, J.

    1985-01-01

    Optical detection is an important technique in studies and observations of air showers, muons and relevant phenomena. The muon intensity is measured in a proper energy range and to study some problems about Cerenkov radiation of cosmic rays are studied, by a muon-telescope operated with Cerenkov detector. It is found that the measured muon intensity agrees with the integral energy spectrum of cosmic ray muons.

  16. Muon front end for the neutrino factory

    NASA Astrophysics Data System (ADS)

    Rogers, C. T.; Stratakis, D.; Prior, G.; Gilardoni, S.; Neuffer, D.; Snopok, P.; Alekou, A.; Pasternak, J.

    2013-04-01

    In the neutrino factory, muons are produced by firing high-energy protons onto a target to produce pions. The pions decay to muons and pass through a capture channel known as the muon front end, before acceleration to 12.6 GeV. The muon front end comprises a variable frequency rf system for longitudinal capture and an ionization cooling channel. In this paper we detail recent improvements in the design of the muon front end.

  17. Muon ID - taking care of lower momenta muons

    SciTech Connect

    Milstene, C.; Fisk, G.; Para, A.; /Fermilab

    2005-12-01

    In the Muon package under study, the tracks are extrapolated using an algorithm which accounts for the magnetic field and the ionization (dE/dx). We improved the calculation of the field dependent term to increase the muon detection efficiency at lower momenta using a Runge-Kutta method. The muon identification and hadron separation in b-bbar jets is reported with the improved software. In the same framework, the utilization of the Kalman filter is introduced. The principle of the Kalman filter is described in some detail with the propagation matrix, with the Runge-Kutta term included, and the effect on low momenta for low momenta single muons particles is described.

  18. Médecine des voyages

    PubMed Central

    Aw, Brian; Boraston, Suni; Botten, David; Cherniwchan, Darin; Fazal, Hyder; Kelton, Timothy; Libman, Michael; Saldanha, Colin; Scappatura, Philip; Stowe, Brian

    2014-01-01

    Résumé Objectif Définir la pratique de la médecine des voyages, présenter les éléments fondamentaux d’une consultation complète préalable aux voyages à des voyageurs internationaux et aider à identifier les patients qu’il vaudrait mieux envoyer en consultation auprès de professionnels de la médecine des voyages. Sources des données Les lignes directrices et les recommandations sur la médecine des voyages et les maladies liées aux voyages publiées par les autorités sanitaires nationales et internationales ont fait l’objet d’un examen. Une recension des ouvrages connexes dans MEDLINE et EMBASE a aussi été effectuée. Message principal La médecine des voyages est une spécialité très dynamique qui se concentre sur les soins préventifs avant un voyage. Une évaluation exhaustive du risque pour chaque voyageur est essentielle pour mesurer avec exactitude les risques particuliers au voyageur, à son itinéraire et à sa destination et pour offrir des conseils sur les interventions les plus appropriées en gestion du risque afin de promouvoir la santé et prévenir les problèmes médicaux indésirables durant le voyage. Des vaccins peuvent aussi être nécessaires et doivent être personnalisés en fonction des antécédents d’immunisation du voyageur, de son itinéraire et du temps qu’il reste avant son départ. Conclusion La santé et la sécurité d’un voyageur dépendent du degré d’expertise du médecin qui offre le counseling préalable à son voyage et les vaccins, au besoin. On recommande à ceux qui donnent des conseils aux voyageurs d’être conscients de l’ampleur de cette responsabilité et de demander si possible une consultation auprès de professionnels de la médecine des voyages pour tous les voyageurs à risque élevé.

  19. LINACS FOR FUTURE MUON FACILITIES

    SciTech Connect

    Slawomir Bogacz, Rolland Johnson

    2008-10-01

    Future Muon Colliders (MC) and Neutrino Factories (NF) based on muon storage rings will require innovative linacs to: produce the muons, cool them, compress longi-tudinally and ‘shape’ them into a beam and finally to rap-idly accelerate them to multi-GeV (NF) and TeV (MC) energies. Each of these four linac applications has new requirements and opportunities that follow from the na-ture of the muon in that it has a short lifetime (τ = 2.2 μsec) in its own rest frame, it is produced in a tertiary process into a large emittance, and its electron, photon, and neutrino decay products can be more than an annoy-ance. As an example, for optimum performance, the linac repetition rates should scale inversely with the laboratory lifetime of the muon in its storage ring, something as high as 1 kHz for a 40 GeV Neutrino Factory or as low as 20 Hz for a 5 TeV Muon Collider. A superconducting 8 GeV Linac capable of CW operation is being studied as a ver-satile option for muon production [1] for colliders, facto-ries, and muon beams for diverse purposes. A linac filled with high pressure hydrogen gas and imbedded in strong magnetic fields has been proposed to rapidly cool muon beams [2]. Recirculating Linear Accelerators (RLA) are possible because muons do not generate significant syn-chrotron radiation even at extremely high energy and in strong magnetic fields. We will describe the present status of linacs for muon applications; in particular the longitu-dinal bunch compression in a single pass linac and multi-pass acceleration in the RLA, especially the optics and technical requirements for RLA designs, using supercon-ducting RF cavities capable of simultaneous acceleration of both μ+ and μ- species, with pulsed linac quadrupoles to allow the maximum number of passes. The design will include the optics for the multi-pass linac and droplet-shaped return arcs.

  20. Muon spin rotation in solids

    NASA Technical Reports Server (NTRS)

    Stronach, C. E.

    1983-01-01

    The muon spin rotation (MuSR) technique is used to probe the microscopic electron density in materials. High temperature MuSR and magnetization measurements in nickel are in progress to allow an unambiguous determination of the muon impurity interaction and the impurity induced change in local spin density. The first results on uniaxial stress induced frequency shifts in an Fe single crystal are also reported.

  1. Muon Colliders: The Next Frontier

    ScienceCinema

    Tourun, Yagmur [Illinois Institute of Technology, Chicago, Illinois, United States

    2010-01-08

    Muon Colliders provide a path to the energy frontier in particle physics but have been regarded to be "at least 20 years away" for 20 years. I will review recent progress in design studies and hardware R&D and show that a Muon Collider can be established as a real option for the post-LHC era if the current vigorous R&D effort revitalized by the Muon Collider Task Force at Fermilab can be supported to its conclusion. All critical technologies are being addressed and no show-stoppers have emerged. Detector backgrounds have been studied in detail and appear to be manageable and the physics can be done with existing detector technology. A muon facility can be built through a staged scenario starting from a low-energy muon source with unprecedented intensity for exquisite reach for rare processes, followed by a Neutrino Factory with ultrapure neutrino beams with unparalleled sensitivity for disentangling neutrino mixing, leading to an energy frontier Muon Collider with excellent energy resolution.

  2. Muon Colliders: The Next Frontier

    SciTech Connect

    Tourun, Yagmur

    2009-07-29

    Muon Colliders provide a path to the energy frontier in particle physics but have been regarded to be 'at least 20 years away' for 20 years. I will review recent progress in design studies and hardware R&D and show that a Muon Collider can be established as a real option for the post-LHC era if the current vigorous R&D effort revitalized by the Muon Collider Task Force at Fermilab can be supported to its conclusion. All critical technologies are being addressed and no show-stoppers have emerged. Detector backgrounds have been studied in detail and appear to be manageable and the physics can be done with existing detector technology. A muon facility can be built through a staged scenario starting from a low-energy muon source with unprecedented intensity for exquisite reach for rare processes, followed by a Neutrino Factory with ultrapure neutrino beams with unparalleled sensitivity for disentangling neutrino mixing, leading to an energy frontier Muon Collider with excellent energy resolution.

  3. Muon Colliders: The Next Frontier

    SciTech Connect

    Tourun, Yagmur

    2009-07-29

    Muon Colliders provide a path to the energy frontier in particle physics but have been regarded to be "at least 20 years away" for 20 years. I will review recent progress in design studies and hardware R&D and show that a Muon Collider can be established as a real option for the post-LHC era if the current vigorous R&D effort revitalized by the Muon Collider Task Force at Fermilab can be supported to its conclusion. All critical technologies are being addressed and no show-stoppers have emerged. Detector backgrounds have been studied in detail and appear to be manageable and the physics can be done with existing detector technology. A muon facility can be built through a staged scenario starting from a low-energy muon source with unprecedented intensity for exquisite reach for rare processes, followed by a Neutrino Factory with ultrapure neutrino beams with unparalleled sensitivity for disentangling neutrino mixing, leading to an energy frontier Muon Collider with excellent energy resolution.

  4. Hyperemesis gravidarum avec troubles ioniques sévères: à propos d'un cas

    PubMed Central

    Jarraya, Anouar; Elleuch, Sahar; Zouari, Jawhar; Trigui, Khaled; Sofiene, Abidi; Smaoui, Mohamed; Kolsi, Kamel

    2015-01-01

    L'hyperemesis gravidarum s'accompagne habituellement d'une perte de poids, d'une acétonurie et de troubles hydro-électrolytiques comme il peut également s'accompagner d'anomalies du bilan hépatique. Nous rapportons un cas de vomissements gravidiques à 10 semaines d'aménorrhée non traité et vu tardivement avec des troubles ioniques sévères associés à des répercussions cliniques dans un contexte de cytolyse, de cholestase et d'insuffisance rénale aigue. Ce cas a bien répondu au traitement médical. PMID:26161187

  5. Quasi-isochronous muon collection channels

    SciTech Connect

    Ankenbrandt, Charles M.; Neuffer, David; Johnson, Rolland P.

    2015-04-26

    Intense muon beams have many potential commercial and scientific applications, ranging from low-energy investigations of the basic properties of matter using spin resonance to large energy-frontier muon colliders. However, muons originate from a tertiary process that produces a diffuse swarm. To make useful beams, the swarm must be rapidly captured and cooled before the muons decay. In this STTR project a promising new concept for the collection and cooling of muon beams to increase their intensity and reduce their emittances was investigated, namely, the use of a nearly isochronous helical cooling channel (HCC) to facilitate capture of the muons into RF bunches. The muon beam can then be cooled quickly and coalesced efficiently to optimize the luminosity of a muon collider, or could provide compressed muon beams for other applications. Optimal ways to integrate such a subsystem into the rest of a muon collection and cooling system, for collider and other applications, were developed by analysis and simulation. The application of quasi-isochronous helical cooling channels (QIHCC) for RF capture of muon beams was developed. Innovative design concepts for a channel incorporating straight solenoids, a matching section, and an HCC, including RF and absorber, were developed, and its subsystems were simulated. Additionally, a procedure that uses an HCC to combine bunches for a muon collider was invented and simulated. Difficult design aspects such as matching sections between subsystems and intensity-dependent effects were addressed. The bunch recombination procedure was developed into a complete design with 3-D simulations. Bright muon beams are needed for many commercial and scientific reasons. Potential commercial applications include low-dose radiography, muon catalyzed fusion, and the use of muon beams to screen cargo containers for homeland security. Scientific uses include low energy beams for rare process searches, muon spin resonance applications, muon beams for

  6. Muon-muon and other high energy colliders

    SciTech Connect

    Palmer, R.B.; Gallardo, J.C.

    1997-02-01

    The first section looks at the high energy physics advantages, disadvantages and luminosity requirements of hadron, of lepton and photon-photon colliders for comparison. The second section discusses the physics considerations for the muon collider. The third section covers muon collider components. The fourth section is about the intersection region and detectors. In the fifth section, the authors discuss modifications to enhance the muon polarization`s operating parameters with very small momentum spreads, operations at energies other than the maximum for which the machine is designed, and designs of machines for different maximum energies. The final section discusses a Research and Development plan aimed at the operation of a 0.5 TeV demonstration machine by the year 2010, and of the 4 TeV machine by the year 2020.

  7. Etude theorique et experimentale des evaporateurs de dioxyde de carbone operant dans des conditions de givrage

    NASA Astrophysics Data System (ADS)

    Bendaoud, Adlane Larbi

    Les evaporateurs de refrigeration sont surtout du type tube a ailettes, appeles serpentins, et fonctionnent dans l'une des conditions suivantes: seche, humide ou avec formation de givre. Il a ete demontre que la formation du givre sur la paroi exterieure de l'echangeur engendre une surconsommation energetique a cause des operations de degivrage puisque 15 a 20% seulement de la chaleur produite sert au degivrage tandis que le reste est dissipee dans l'environnement [1]. Avec l'avenement des nouveaux refrigerants, moins nocifs envers l'environnement, l'industrie du froid se trouve penalisee du fait que peu ou pas de composantes mecaniques (compresseur, pompe, echangeur...etc.) adaptees sont disponibles [3]. Il s'agit pour la communaute des frigoristes de combler ce retard technologique en redeveloppant ces composantes mecaniques afin qu'elles soient adaptees aux nouveaux refrigerants. Dans cette optique, et afin de mieux comprendre le comportement thermique des evaporateurs au CO2 fonctionnant dans des conditions seches, qu'un groupe de chercheurs du CanmetENERGIE avaient lance, en 2000, un programme de R & D. Dans le cadre de programme un outil de simulation des evaporateurs au CO2 a ete developpe et un banc d'essai contenant une boucle secondaire de refrigeration utilisant le CO2 comme refrigerant a ete construit. Comme continuite de ce travail de recherche, en 2006 ce meme groupe de recherche a lance un nouveau projet qui consiste a faire une etude theorique et experimentale des evaporateurs au CO2 operants dans des conditions de givrage. Et, c'est exactement dans le cadre de ce projet que se positionne ce travail de these. Ce travail de recherche a ete entrepris pour mieux comprendre le comportement thermique et hydrodynamique des serpentins fonctionnant dans des conditions de givrage, l'effet des circuits de refrigerant ainsi que celui des parametres geometriques et d'operation. Pour cela, un travail theorique supporte par une etude experimentale a ete effectue

  8. Muon motion in titanium hydride

    NASA Technical Reports Server (NTRS)

    Kempton, J. R.; Petzinger, K. G.; Kossler, W. J.; Schone, H. E.; Hitti, B. S.; Stronach, C. E.; Adu, N.; Lankford, W. F.; Reilly, J. J.; Seymour, E. F. W.

    1988-01-01

    Motional narrowing of the transverse-field muon spin rotation signal was observed in gamma-TiH(x) for x = 1.83, 1.97, and 1.99. An analysis of the data for TiH1.99 near room temperature indicates that the mechanism responsible for the motion of the muon out of the octahedral site is thermally activated diffusion with an attempt frequency comparable to the optical vibrations of the lattice. Monte Carlo calculations to simulate the effect of muon and proton motion upon the muon field-correlation time were used to interpret the motional narrowing in TiH1.97 near 500 K. The interpretation is dependent upon whether the Bloembergen, Purcell, and Pound (BPP) theory or an independent spin-pair relaxation model is used to obtain the vacancy jump rate from proton NMR T1 measurements. Use of BPP theory shows that the field-correction time can be obtained if the rate of motion of the muon with respect to the rate of the motion for the protons is decreased. An independent spin-pair relaxation model indicates that the field-correlation time can be obtained if the rate of motion for the nearest-neighbor protons is decreased.

  9. Pneumopathie grave avec atteinte bronchique compliquant une varicelle chez un adulte immunocompétent

    PubMed Central

    Serghini, Issam; Chkoura, Khalid; Hjira, Nawfal; Zoubir, Mohamed; Lalaoui; Boughalem, Mohamed

    2014-01-01

    La varicelle est une infection virale cosmopolite, très contagieuse, due au virus varicelle-zona (VZV) et caractérisée par de la fièvre et une éruption papulo-vésiculeuse prurigineuse. L'incidence de la varicelle a significativement augmenté dans les dernières décennies en Europe et aux États-Unis. Chez l'enfant, la varicelle est une infection habituellement bénigne. Chez l'adulte, son évolution peut être émaillée de complications. La pneumonie varicelleuse est la plus fréquente des complications graves de la varicelle chez l'adulte, avec une incidence estimée de 16 à 33% et une mortalité pouvant atteindre 20%. Nous rapportons un cas de varicelle compliquée d'une pneumopathie hypoxémiante. L'examen endoscopique bronchique met en évidence des lésions vésiculeuses de la muqueuse bronchique. Sous traitement antiviral, l’évolution est favorable. PMID:25829973

  10. Muon-Pair Production by Atmospheric Muons in CosmoALEPH

    SciTech Connect

    Maciuc, F.; Grupen, C.; Hashim, N.O.; Luitz, S.; Mailov, A.; Muller, A.S.; Putzer, A.; Sander, H.G.; Schmeling, S.; Schmelling, M.; Tcaciuc, R.; Wachsmuth, H.; Ziegler, T.; Zuber, K.; /Heidelberg, Max Planck Inst. /Siegen U. /SLAC /Karlsruhe, Forschungszentrum /Heidelberg U. /Mainz U., Inst. Phys. /CERN /Princeton U. /Oxford U.

    2006-03-06

    Data from a dedicated cosmic ray run of the ALEPH detector were used in a study of muon trident production, i.e., muon pairs produced by muons. Here the overburden and the calorimeters are the target materials while the ALEPH time projection chamber provides the momentum measurements. A theoretical estimate of the muon trident cross section is obtained by developing a Monte Carlo simulation for muon propagation in the overburden and the detector. Two muon trident candidates were found to match the expected theoretical pattern. The observed production rate implies that the nuclear form factor cannot be neglected for muon tridents.

  11. Muon collider interaction region design

    SciTech Connect

    Alexahin, Y.I.; Gianfelice-Wendt, E.; Kashikhin, V.V.; Mokhov, N.V.; Zlobin, A.V.; Alexakhin, V.Y.; /Dubna, JINR

    2010-05-01

    Design of a muon collider interaction region (IR) presents a number of challenges arising from low {beta}* < 1 cm, correspondingly large beta-function values and beam sizes at IR magnets, as well as the necessity to protect superconducting magnets and collider detectors from muon decay products. As a consequence, the designs of the IR optics, magnets and machine-detector interface are strongly interlaced and iterative. A consistent solution for the 1.5 TeV c.o.m. muon collider IR is presented. It can provide an average luminosity of 10{sup 34} cm{sup -2}s{sup -1} with an adequate protection of magnet and detector components.

  12. Law of Conservation of Muons

    DOE R&D Accomplishments Database

    Feinberg, G.; Weinberg, S.

    1961-02-01

    A multiplicative selection rule for mu meson-electron transitions is proposed. A "muon parity" = -1 is considered for the muon and its neutrino, while the "muon parity" for all other particles is +1. The selection rule then states that (-1) exp(no. of initial (-1) parity particles) = (-1) exp(no. of final (-1) parity particles). Several reactions that are forbidden by an additive law but allowed by the multiplicative law are suggested; these reactions include mu{sup +} .> e{sup +} + nu{sub mu} + {ovr nu}{sub e}, e{sup -} + e{sup -} .> mu{sup -} + mu{sup -}, and muonium .> antimuonium (mu{sup +} + e{sup -} .> mu{sup -} + e{sup +}). An intermediate-boson hypothesis is suggested. (T.F.H.)

  13. The MICE Muon Beam Line

    SciTech Connect

    Apollonio, Marco

    2011-10-06

    In the Muon Ionization Cooling Experiment (MICE) at RAL, muons are produced and transported in a dedicated beam line connecting the production point (target) to the cooling channel. We discuss the main features of the beamline, meant to provide muons with momenta between 140 MeV/c and 240 MeV/c and emittances up to 10 mm rad, which is accomplished by means of a diffuser. Matching procedures to the MICE cooling channel are also described. In summer 2010 we performed an intense data taking campaign to finalize the calibration of the MICE Particle Identification (PID) detectors and the understanding of the beam line, which completes the STEPI phase of MICE. We highlight the main results from these data.

  14. Detection du tore de poussieres dans les noyaux actifs de galaxies avec COMIC, la nouvelle camera infrarouge du systeme d'optique adaptative de l'ESO. (Resume de these).

    NASA Astrophysics Data System (ADS)

    Marco, O.

    1998-05-01

    L'observation a haute resolution angulaire a connu un nouvel elan avec la mise au point de systemes d'optique adaptative fonctionnant dans l'infrarouge. La camera COMIC, seconde camera dediee a ADONIS, le systeme d'optique adaptative equipant le telescope de 3.60 metres de l'ESO, permet l'observation dans le domaine spectral 3-5 microns a la limite de resolution angulaire du telescope. La caracterisation de la camera au laboratoire a Meudon et Grenoble, puis la determination de ses performances sur le site au Chili sont l'objet de la premiere partie de cette These. Une methode originale d'evaluation des magnitudes limites atteintes est proposee, qui prend en compte a chaque stade les differents facteurs de perte de detectivite entre les mesures au laboratoire et celles en conditions reelles. Cette approche pourra etre envisagee chaque fois que l'on a connaissance a priori des conditions d'observation (quantifiees en particulier par le rapport de Strehl, ou encore par une estimation du seeing). L'etude de la region centrale (~1 arcsec) des Noyaux Actifs de Galaxies necessite l'acces a la haute resolution angulaire. En particulier, la poussiere chaude emet dans le domaine 1-5 microns. L'observation des NAG avec un systeme d'optique adaptative est donc tout indiquee. La theorie d'unification des NAG prevoit la presence d'un tore moleculaire et poussiereux, responsable d'effets masquant selon l'angle de visee sous lequel on les observe, induisant des proprietes observationnelles distinctes pour des objets supposes identiques. Les observations real isees avec ADONIS & COMIC de NGC 7469 et NGC 1068 ont montre la presence d'une grande quantite de poussieres chaudes localisees a l'emplacement du tore presume, mais aussi melangees avec le gaz de la region d'emission de raies etroites. La haute resolution angulaire atteinte a permis de preciser la temperature des poussieres chaudes, leur masse, et leur distribution spatiale autour de la source centrale du NAG. Ces resultats

  15. MICE: The International Muon Ionization Cooling Experiment

    SciTech Connect

    Kaplan, Daniel M.

    2006-03-20

    Ionization cooling of a muon beam is a key technique for a Neutrino Factory or Muon Collider. An international collaboration is mounting an experiment to demonstrate muon ionization cooling at the Rutherford Appleton Laboratory. We aim to complete the experiment by 2010.

  16. A Highly intense DC muon source, MuSIC and muon CLFV search

    NASA Astrophysics Data System (ADS)

    Hino, Y.; Kuno, Y.; Sato, A.; Sakamoto, H.; Matsumoto, Y.; Tran, N. H.; Hashim, I. H.; Fukuda, M.; Hayashida, Y.; Ogitsu, T.; Yamamoto, A.; Yoshida, M.

    2014-08-01

    MuSIC is a new muon facility, which provides the world's highest intense muon beam with continuous time structure at Research Center of Nuclear Physics (RCNP), Osaka University. It's intensity is designed to be 108 muons per second with only 0.4 kW proton beam. Such a high intense muon beam is very important for searches of rare decay processes, for example search for the muon to electron conversion.

  17. Profil epidemiologique des brulures d'enfants admis au Centre National des Brules, Maroc

    PubMed Central

    Zahid, A.; Atannaz, J.; Alaoui, M.; Rafik, A.; Ezzoubi, M.; Diouri, M.; Chlihi, A.; Bahechar, N.; Boukind, E.H.

    2011-01-01

    Summary Ce travail rétrospectif analyse les particularités épidémiologiques de 543 cas de brûlures d'enfants, représentant 45,7% des admissions de notre centre, en vue de déterminer les éléments pouvant contribuer à renforcer la prévention, qui reste le traitement de choix de cette pathologie. La moyenne d'âge est de 4,25 ans avec une prédilection pour la tranche d'âge d'un à cinq ans, avec 42,5% des cas. Une atteinte masculine est retrouvée dans 63,5% des cas. La brûlure survient à domicile dans 85,1% et accidentellement dans 95% des cas. Les brûlures thermiques représentent 96,5% des causes dominées par les liquides dans 69,3% des cas. La surface cutanée brûlée est ≥ 20% dans 52,3%. La brûlure intéresse essentiellement les membres supérieurs (79,1%). 56,8% des enfants sont transférés par d'autres hôpitaux et le délai de prise en charge hospitalière est supérieur à 6 heures dans 65,5%. Le taux de mortalité a été de 13,2%. PMID:22639559

  18. Physics with a millimole of muons

    SciTech Connect

    Quigg, C.

    1998-03-01

    The eventual prospect of muon colliders reaching several TeV encourages us to consider the experimental opportunities presented by very copious stores of muons, approaching 10{sup 21} per year. I summarize and comment upon some highlights of the Fermilab Workshop on Physics at the First Muon Collider and at the Front End of a Muon Collider. Topics include various varieties of {mu}{mu} colliders, {mu}p colliders, and applications of the intense neutrino beams that can be generated in muon storage rings.

  19. Superconducting magnet system for muon beam cooling

    SciTech Connect

    Andreev, N.; Johnson, R.P.; Kashikhin, V.S.; Kashikhin, V.V.; Novitski, I.; Yonehara, K.; Zlobin, A.; /Fermilab

    2006-08-01

    A helical cooling channel has been proposed to quickly reduce the six-dimensional phase space of muon beams for muon colliders, neutrino factories, and intense muon sources. A novel superconducting magnet system for a muon beam cooling experiment is being designed at Fermilab. The inner volume of the cooling channel is filled with liquid helium where passing muon beam can be decelerated and cooled in a process of ionization energy loss. The magnet parameters are optimized to match the momentum of the beam as it slows down. The results of 3D magnetic analysis for two designs of magnet system, mechanical and quench protection considerations are discussed.

  20. L’identification et traitement du trouble panique avec ou sans agoraphobie

    PubMed Central

    Foldes-Busque, Guillaume; Marchand, André; Landry, Pierre

    2007-01-01

    RÉSUMÉ OBJECTIF Renseigner les médecins de première ligne au sujet de l’identification précoce, du diagnostic et du traitement du trouble panique avec ou sans agoraphobie (TP/A). QUALITÉ DES DONNÉES Les données et recommandations présentées proviennent d’une recension des écrits scientifiques réalisée via les banques de données PsycLIT, PsyINFO et MEDLINE (1985 à 2006) en utilisant les descripteurs panic disorder, psychotherapy, psychosocial treatment, treatment et pharmacotherapy. Les recommandations formulées par les auteurs s’appuient sur des données probantes provenant d’études d’excellente qualité. Les informations concernant le diagnostic et l’évaluation du TP/A proviennent d’études épidémiologiques récentes, de consensus et d’opinions d’experts. PRINCIPAL MESSAGE Le TP/A est un trouble psychiatrique souvent rencontré en médecine de première ligne, mais il est fréquemment sous-diagnostiqué et sous-traité. L’identification précoce de ce trouble demande une attention particulière aux symptômes médicalement inexpliqués et, le cas échéant, le médecin doit utiliser des questions spécifiques permettant d’identifier d’éventuelles attaques de panique et de cerner leur signification pour le patient. Le traitement de premier choix pour ce trouble est une psychothérapie d’orientation cognitivo-comportementale administrée par un psychologue ou un psychiatre spécialisé. Si de telles ressources ne sont pas disponibles, le médecin peut opter pour un traitement psychopharmacologique. CONCLUSION Les médecins de famille peuvent jouer un rôle central dans l’identification et le traitement des patients souffrant d’un TP/A. PMID:17934032

  1. Design Concepts for Muon-Based Accelerators

    SciTech Connect

    Ryne, R. D.; Berg, J. S.; Kirk, H. G.; Palmer, R. B.; Stratkis, D.; Alexahin, Y.; Bross, A.; Gollwitzer, K.; Mokhov, N. V.; Neuffer, D.; Palmer, M. A.; Yonehara, K.; Snopok, P.; Bogacz, A.; Roberts, T. J.; Delahaye, J. -P.

    2015-05-01

    Muon-based accelerators have the potential to enable facilities at both the Intensity and the Energy Frontiers. Muon storage rings can serve as high precision neutrino sources, and a muon collider is an ideal technology for a TeV or multi-TeV collider. Progress in muon accelerator designs has advanced steadily in recent years. In regard to 6D muon cooling, detailed and realistic designs now exist that provide more than 5 order-of-magnitude emittance reduction. Furthermore, detector performance studies indicate that with suitable pixelation and timing resolution, backgrounds in the collider detectors can be significantly reduced, thus enabling high-quality physics results. Thanks to these and other advances in design & simulation of muon systems, technology development, and systems demonstrations, muon storage-ring-based neutrino sources and a muon collider appear more feasible than ever before. A muon collider is now arguably among the most compelling approaches to a multi-TeV lepton collider. This paper summarizes the current status of design concepts for muon-based accelerators for neutrino factories and a muon collider.

  2. Neutrino Factory and Muon Collider Fellow

    SciTech Connect

    Hanson, Gail G.; Snopak, Pavel; Bao, Yu

    2015-03-20

    Muons are fundamental particles like electrons but much more massive. Muon accelerators can provide physics opportunities similar to those of electron accelerators, but because of the larger mass muons lose less energy to radiation, allowing more compact facilities with lower operating costs. The way muon beams are produced makes them too large to fit into the vacuum chamber of a cost-effective accelerator, and the short muon lifetime means that the beams must be reduced in size rather quickly, without losing too many of the muons. This reduction in size is called "cooling." Ionization cooling is a new technique that can accomplish such cooling. Intense muon beams can then be accelerated and injected into a storage ring, where they can be used to produce neutrino beams through their decays or collided with muons of the opposite charge to produce a muon collider, similar to an electron-positron collider. We report on the research carried out at the University of California, Riverside, towards producing such muon accelerators, as part of the Muon Accelerator Program based at Fermilab. Since this research was carried out in a university environment, we were able to involve both undergraduate and graduate students.

  3. Muon g-2 Experiment Shimming

    ScienceCinema

    Kiburg, Brendan

    2016-06-28

    The Muon g-2 experiment at Fermilab will use as its primary instrument a 52-foot-wide electromagnet that creates a precise magnetic field. In this video, Fermilab's Brendan Kiburg explains the lengthy process of finely "shimming" that magnetic field into shape.

  4. Cosmic muons, as messengers from the Universe

    NASA Astrophysics Data System (ADS)

    Brancus, I. M.; Rebel, H.

    2015-02-01

    Penetrating from the outer space into the Earth atmosphere, primary cosmic rays are producing secondary radiation by the collisions with the air target subsequently decaying in hadrons, pions, muons, electrons and photons, phenomenon called Extensive air Shower (EAS). The muons, considered as the "penetrating" component, survive the propagation to the Earth and even they are no direct messenger of the Universe, they reflect the features of the primary particles. The talk gives a description of the development of the extensive air showers generating the secondary particles, especially the muon component. Results of the muon flux and of the muon charge ratio, (the ratio between the positive and the negative muons), obtained in different laboratories and in WILLI experiment, are shown. At the end, the contribution of the muons measured in EAS to the investigation of the nature of the primary cosmic rays is emphasized in KASCADE and WILLI-EAS experiments.

  5. Cosmic muons, as messengers from the Universe

    SciTech Connect

    Brancus, I. M.; Rebel, H.

    2015-02-24

    Penetrating from the outer space into the Earth atmosphere, primary cosmic rays are producing secondary radiation by the collisions with the air target subsequently decaying in hadrons, pions, muons, electrons and photons, phenomenon called Extensive air Shower (EAS). The muons, considered as the “penetrating” component, survive the propagation to the Earth and even they are no direct messenger of the Universe, they reflect the features of the primary particles. The talk gives a description of the development of the extensive air showers generating the secondary particles, especially the muon component. Results of the muon flux and of the muon charge ratio, (the ratio between the positive and the negative muons), obtained in different laboratories and in WILLI experiment, are shown. At the end, the contribution of the muons measured in EAS to the investigation of the nature of the primary cosmic rays is emphasized in KASCADE and WILLI-EAS experiments.

  6. Pion contamination in the MICE muon beam

    NASA Astrophysics Data System (ADS)

    Adams, D.; Alekou, A.; Apollonio, M.; Asfandiyarov, R.; Barber, G.; Barclay, P.; de Bari, A.; Bayes, R.; Bayliss, V.; Bertoni, R.; Blackmore, V. J.; Blondel, A.; Blot, S.; Bogomilov, M.; Bonesini, M.; Booth, C. N.; Bowring, D.; Boyd, S.; Brashaw, T. W.; Bravar, U.; Bross, A. D.; Capponi, M.; Carlisle, T.; Cecchet, G.; Charnley, C.; Chignoli, F.; Cline, D.; Cobb, J. H.; Colling, G.; Collomb, N.; Coney, L.; Cooke, P.; Courthold, M.; Cremaldi, L. M.; DeMello, A.; Dick, A.; Dobbs, A.; Dornan, P.; Drews, M.; Drielsma, F.; Filthaut, F.; Fitzpatrick, T.; Franchini, P.; Francis, V.; Fry, L.; Gallagher, A.; Gamet, R.; Gardener, R.; Gourlay, S.; Grant, A.; Greis, J. R.; Griffiths, S.; Hanlet, P.; Hansen, O. M.; Hanson, G. G.; Hart, T. L.; Hartnett, T.; Hayler, T.; Heidt, C.; Hills, M.; Hodgson, P.; Hunt, C.; Iaciofano, A.; Ishimoto, S.; Kafka, G.; Kaplan, D. M.; Karadzhov, Y.; Kim, Y. K.; Kuno, Y.; Kyberd, P.; Lagrange, J.-B.; Langlands, J.; Lau, W.; Leonova, M.; Li, D.; Lintern, A.; Littlefield, M.; Long, K.; Luo, T.; Macwaters, C.; Martlew, B.; Martyniak, J.; Mazza, R.; Middleton, S.; Moretti, A.; Moss, A.; Muir, A.; Mullacrane, I.; Nebrensky, J. J.; Neuffer, D.; Nichols, A.; Nicholson, R.; Nugent, J. C.; Oates, A.; Onel, Y.; Orestano, D.; Overton, E.; Owens, P.; Palladino, V.; Pasternak, J.; Pastore, F.; Pidcott, C.; Popovic, M.; Preece, R.; Prestemon, S.; Rajaram, D.; Ramberger, S.; Rayner, M. A.; Ricciardi, S.; Roberts, T. J.; Robinson, M.; Rogers, C.; Ronald, K.; Rubinov, P.; Rucinski, P.; Sakamato, H.; Sanders, D. A.; Santos, E.; Savidge, T.; Smith, P. J.; Snopok, P.; Soler, F. J. P.; Speirs, D.; Stanley, T.; Stokes, G.; Summers, D. J.; Tarrant, J.; Taylor, I.; Tortora, L.; Torun, Y.; Tsenov, R.; Tunnell, C. D.; Uchida, M. A.; Vankova-Kirilova, G.; Virostek, S.; Vretenar, M.; Warburton, P.; Watson, S.; White, C.; Whyte, C. G.; Wilson, A.; Winter, M.; Yang, X.; Young, A.; Zisman, M.

    2016-03-01

    The international Muon Ionization Cooling Experiment (MICE) will perform a systematic investigation of ionization cooling with muon beams of momentum between 140 and 240 MeV/c at the Rutherford Appleton Laboratory ISIS facility. The measurement of ionization cooling in MICE relies on the selection of a pure sample of muons that traverse the experiment. To make this selection, the MICE Muon Beam is designed to deliver a beam of muons with less than ~1% contamination. To make the final muon selection, MICE employs a particle-identification (PID) system upstream and downstream of the cooling cell. The PID system includes time-of-flight hodoscopes, threshold-Cherenkov counters and calorimetry. The upper limit for the pion contamination measured in this paper is fπ < 1.4% at 90% C.L., including systematic uncertainties. Therefore, the MICE Muon Beam is able to meet the stringent pion-contamination requirements of the study of ionization cooling.

  7. NEUTRINO FACTORY BASED ON MUON-STORAGE-RINGS TO MUON COLLIDERS: PHYSICS AND FACILITIES.

    SciTech Connect

    PARSA,Z.

    2001-06-18

    Intense muon sources for the purpose of providing intense high energy neutrino beams ({nu} factory) represents very interesting possibilities. If successful, such efforts would significantly advance the state of muon technology and provides intermediate steps in technologies required for a future high energy muon collider complex. High intensity muon: production, capture, cooling, acceleration and multi-turn muon storage rings are some of the key technology issues that needs more studies and developments, and will briefly be discussed here. A muon collider requires basically the same number of muons as for the muon storage ring neutrino factory, but would require more cooling, and simultaneous capture of both {+-} {mu}. We present some physics possibilities, muon storage ring based neutrino facility concept, site specific examples including collaboration feasibility studies, and upgrades to a full collider.

  8. Profil anthropometrique des enfants scolarises tananariviens

    PubMed Central

    Razafimanantsoa, Fetralinjiva; Razafindramaro, Notahiana; Raherimandimby, Hasina; Robinson, Annick; RakotoAlson, Olivat; Rasamindrakotroka, Andry

    2013-01-01

    Les enfants tananariviens sont en état de malnutrition chronique. Notre objectif est d’évaluer l'indice de masse corporelle (IMC) pour estimer les enfants apparemment "sains". Une enquête et une mesure de la taille et du poids des enfants scolarisés tananariviens de 6 à 11 ans ont été réalisées. Après leur accord, la taille et l'indice de masse corporelle des 442 enfants tirés au hasard ont été ainsi obtenus. L'analyse de la moyenne de la taille a révélé une différence significative à 8 ans, une différence non évidente sur l'indice de masse corporelle. La comparaison avec les valeurs de référence (OMS 2006) a montré un retard statural de 34% avec une tendance globale à la hausse et un déficit pondéral égal à 5,5% selon le z score. Ainsi, au sein d'une population malnutrie, l'indice de masse corporelle pourrait être utilisé comme un des paramètres à considérer dans l’évaluation de l’état de santé pour classer ces enfants en bonne santé apparente. PMID:24711862

  9. Méningiome en plaque sphéno-orbitaire: à propos d'un cas avec revue de la littérature

    PubMed Central

    Abdellaoui, Meriem; Andaloussi, Idriss Benatiya; Tahri, Hicham

    2015-01-01

    Le méningiome intra osseux est une variété des méningiomes ectopiques dans lequel les cellules méningothéliales envahissent la paroi osseuse et entraînent une hyperostose. Le méningiome en plaque, variante macroscopique des méningiomes intra osseux, est une tumeur rare et survient fréquemment au niveau de la région sphéno-orbitaire ce qui le confond avec les tumeurs osseuses primitives. Nous rapportons le cas d'une patiente de 50 ans qui présente une exophtalmie avec cécité unilatérale gauche d'installation progressive depuis un an. L'examen trouve une exophtalmie axile, indolore et non réductible ainsi qu'une limitation de la motilité oculaire dans tous les sens du regard. La palpation montre une masse temporale gauche dure et adhérente à l'os. L'examen du fond d’œil trouve un œdème papillaire gauche. Le scanner montre une lésion ostéocondensante temporo-sphéno-orbitaire gauche avec envahissement locorégional. Le diagnostic préopératoire fut une tumeur osseuse essentiellement maligne primitive ou secondaire. L’étude histologique a révélée un méningiome meningothélial de type en plaque. La patiente a bénéficié d'une exérèse avec reconstruction chirurgicale. Aucune récidive n'a été notée après 1 an de recul. PMID:26327996

  10. Simulation of large acceptance LINAC for muons

    SciTech Connect

    Miyadera, H; Kurennoy, S; Jason, A J

    2010-01-01

    There has been a recent need for muon accelerators not only for future Neutrino Factories and Muon Colliders but also for other applications in industry and medical use. We carried out simulations on a large-acceptance muon linac with a new concept 'mixed buncher/acceleration'. The linac can accept pions/muons from a production target with large acceptance and accelerate muon without any beam cooling which makes the initial section of muon-linac system very compact. The linac has a high impact on Neutrino Factory and Muon Collider (NF/MC) scenario since the 300-m injector section can be replaced by the muon linac of only 10-m length. The current design of the linac consists of the following components: independent 805-MHz cavity structure with 6- or 8-cm-radius aperture window; injection of a broad range of pion/muon energies, 10-100 MeV, and acceleration to 150 - 200 MeV. Further acceleration of the muon beam are relatively easy since the beam is already bunched.

  11. La détermination des distances: Sol, Hipparcos, GAIA.

    NASA Astrophysics Data System (ADS)

    Turon, C.

    Les parallaxes trigonométriques des étoiles les plus proches du soleil sont la base de la détermination des distances dans l'Univers. Elles permettent, par la calibration en luminosité des différents indicateurs de distance d'étalonner les distances d'abord dans notre Galaxie, puis dans les galaxies du Groupe Local, puis pour les galaxies plus lointaines. Cette base est, actuellement, très mince, et peu de types d'étoiles y sont représentés. Hipparcos va déjà apporter une amélioration sensible. Avec GAIA une révision complète des calibrations de luminosité de tous les indicateurs "primaires" serait directement possible.

  12. Directivity function of muon detector

    NASA Astrophysics Data System (ADS)

    Karapetyan, G. G.

    2015-02-01

    We introduce a new concept of directivity function (DF) to describe directional sensitivity of a particle detector. DF is a 3D function, describing the sensitivity of a detector to asymptotic directions of primary protons. It defines the contribution of primary protons, arriving from different asymptotic directions to the count rate of the detector. We develop the approach for computing the DF and derive it in particular case of SEVAN muon detector, located at mount Aragats, Armenia. Obtained data enable one to outline the region of solid angles, inside of which the arriving protons contribute a given percentage of count rate. In general, the DF can have the multi peak shape. It provides the most detailed and accurate description of directional sensitivity of a particle detector and we suggest that it is used in space research based on neutron and muon detectors.

  13. Muon data analysis program RUMDA

    NASA Astrophysics Data System (ADS)

    Kilcoyne, S. H.

    1994-07-01

    There are currently two data analysis programs available for muon users at ISIS. Both programs can be used for analyzing MuSR and EMU data and can be run on (MUSR01), (EMU01) or set-up to run on a user's account. RUMDA - 'Reading University Muon Data Analysis' was originally from Reading University and is now controlled at ISIS. At present (mid 1994) this suite of programs is run using VAX/VMS and the ISIS plotting package 'GENIE'. It is possible to fit data to any function with a maximum of 10 variables. UDA - 'mu Data Analysis' is a dashboard driven program which allows the user to plot and fit data files on the screen or as hard copies. It is possible to fit data to a combination of Gaussian and/or Lorentzian line shapes. A manual describing this program can be found in the back of the MuSR User Guide.

  14. The first muon beam from a new highly-intense DC muon source, MuSIC

    NASA Astrophysics Data System (ADS)

    Tran, Nam Hoai; MuSIC Collaboration

    2012-09-01

    A new DC muon source, MuSIC, is now under construction at Research Center for Nuclear Physics (RCNP), Osaka University, Japan. The MuSIC adopts a new pion/muon collection system and a curved transport solenoid. These techniques are important in realization of future muon programs such as the muon to electron conversion experiments (COMET/Mu2e), neutrino factories, and muon colliders. The pion capture magnet and a part of the transport solenoid have been built and beam tests were carried out to assess the MuSIC's performance. Muon lifetime measurements and muonic X-ray measurements have been used for estimation of muon yield of the MuSIC. The result indicates that the MuSIC would be one of the most intense DC muon beams in the world.

  15. Muon ID at the ILC

    SciTech Connect

    Milstene, C.; Fisk, G.; Para, A.; /Fermilab

    2006-09-01

    This paper describes a new way to reconstruct and identify muons with high efficiency and high pion rejection. Since muons at the ILC are often produced with or in jets, for many of the physics channels of interest [1], an efficient algorithm to deal with the identification and separation of particles within jets is important. The algorithm at the core of the method accounts for the effects of the magnetic field and for the loss of energy by charged particles due to ionization in the detector. We have chosen to develop the analysis within the setup of one of the Linear Collider Concept Detectors adopted by the US. Within b-pair production jets, particles cover a wide range in momenta; however {approx}80% of the particles have a momentum below 30 GeV[2]. Our study, focused on bbar-b jets, is preceded by a careful analysis of single energy particles between 2 and 50 GeV. As medium energy particles are a substantial component of the jets, many of the particles lose part of their energy in the calorimeters and the solenoid coil before reaching the muon detector where they may have energy below 2 GeV. To deal with this problem we have implemented a Runge-Kutta correction of the calculated trajectory to better handle these lower energy particles. The multiple scattering and other stochastic processes, more important at lower energy, is addressed by a Kalman-filter integrated into the reconstruction algorithm. The algorithm provides a unique and powerful separation of muons from pions. The 5 Tesla magnetic field from a solenoid surrounds the hadron calorimeter and allows the reconstruction and precision.

  16. Neutron densities from muon capture

    NASA Astrophysics Data System (ADS)

    Huan Ching, Chiang; Oset, Eulogio

    1991-10-01

    We show that, because of Pauli blocking and renormalization of the weak currents in nuclei, the muon capture rates are rather sensitive to the neutron distributions. We also show that, because of intrinsic theoretical uncertainties, neutron radia cannot be determined with precision but some reasonable limits can be given. However, the ratio of capture rates in different isotopes serves to determine the neutron radii of the isotopes provided the neutron density distribution for one of them is known.

  17. Introduction to Mini Muon Tracker

    SciTech Connect

    Borozdin, Konstantin N.

    2012-08-13

    Using a mini muon tracker developed at the Los Alamos National Laboratory we performed experiments of simple landscapes of various materials, including TNT, 9501, lead, tungsten, aluminium, and water. Most common scenes are four two inches thick step wedges of different dimensions: 12-inch x 12-inch, 12-inch x 9-inch, 12-inch x 6-inch, and 12-inch x 3-inch; and a one three inches thick hemisphere of lead with spherical hollow, and a similar full lead sphere.

  18. Information extraction from muon radiography data

    SciTech Connect

    Borozdin, K. N.; Asaki, T. J.; Chartrand, R.; Hengartner, N. W.; Hogan, G. E.; Morris, C. L.; Priedhorsky, W. C.; Schirato, R.C.; Schultz, L. J.; Sottile, M. J.; Vixie, K. R.; Wohlberg, B. E.; Blanpied, G.

    2004-01-01

    Scattering muon radiography was proposed recently as a technique of detection and 3-d imaging for dense high-Z objects. High-energy cosmic ray muons are deflected in matter in the process of multiple Coulomb scattering. By measuring the deflection angles we are able to reconstruct the configuration of high-Z material in the object. We discuss the methods for information extraction from muon radiography data. Tomographic methods widely used in medical images have been applied to a specific muon radiography information source. Alternative simple technique based on the counting of high-scattered muons in the voxels seems to be efficient in many simulated scenes. SVM-based classifiers and clustering algorithms may allow detection of compact high-Z object without full image reconstruction. The efficiency of muon radiography can be increased using additional informational sources, such as momentum estimation, stopping power measurement, and detection of muonic atom emission.

  19. Diffusion des Metaux et Evolution Stellaire

    NASA Astrophysics Data System (ADS)

    Turcotte, Sylvain

    Nous presentons dans cette these des modeles d'evolution stellaire incorporant la diffusion microscopique de maniere consistante. Pour la premiere fois, on a calcule l'evolution d'etoiles en tenant compte en detail de l'impact des variations d'abondances sur leur structure. Nous utilisons des spectres monochromatiques pour chacun des elements les plus abondants dans un melange solaire pour recalculer l'opacite pour les abondances et les conditions locales dans l'interieur d'une etoile au cours de son evolution. Nos modeles montrent que la diffusion atomique des metaux a un effet important sur les opacites dan les etoiles de plus de 1.3Msolar ou l'abondance du fer et des autres elements du pic du fer varient substantiellement. Ces etoiles, sans rotation ou champ magnetique, sont proches des etoiles de type Fm-Am dans lesquelles on observe une legere surabondance d'elements du pic du fer en plus d'une sous-abondance de calcium, sous-abondance que l'on obtient egalement. Nous obtenons cependant des surabondances depassant un facteur 10 pour les etoiles de plus de 1.4Msolar ce qui suggere qu'il existe un ou plusieurs mecanismes limitant la diffusion microscopique. La surabondance du fer en surface cause une augmentation, qui peut atteindre un facteur sept, de l'opacite a la limite de la zone convective. Ceci cause un accroissement de la temperature effective et de la masse de la zone convective comparativement aux modeles n'incluant que la diffusion de l'helium. Il s'agit la du principal effet de la diffusion sur la structure interne de ces etoiles. La diffusions n'a pas d'influence sur l'evolution de coeur stellaire dans les etoiles significativement plus massives quie le Soleil. Nous avons verife que l'utilisation de modeles consistants avec diffusion n'apporte pas d'amelioration sensible aux modeles solaires. Les forces radiatives calculees a partir des spectres d'OPAL pour les elements du pic du fer representent une fraction importante de la gravite. On obtient des

  20. Muon cooling in a quadrupole magnet channel

    SciTech Connect

    Neuffer, David; Poklonskiy, A.; /Michigan State U.

    2007-10-01

    As discussed before,[1] a cooling channel using quadrupole magnets in a FODO transport channel can be used for initial cooling of muons. In the present note we discuss this possibility of a FODO focusing channel for cooling, and we present ICOOL simulations of muon cooling within a FODO channel. We explore a 1.5m cell-length cooling channel that could be used for the initial transverse cooling stage of a muon collider or neutrino factory.

  1. Status of the MANX muon cooling experiment

    SciTech Connect

    Yonehara, K.; Broemmelsiek, D.; Hu, M.; Jansson, A.; Kashikhin, V.S.; Kashikhin, V.V.; Lamm, M.; Lopes, M.; Shiltsev, V.; Yarba, V.; Yu, M.; /Fermilab /Muons Inc., Batavia

    2008-06-01

    A demonstration experiment of six-dimensional (6D) phase space muon beam cooling is a key milestone on the roadmap toward to a real muon collider. In order to achieve this goal, they have designed the Muon Collider and Neutrino Factory Experiment (MANX) channel, which consists of the Helical Cooling Channel (HCC). They discuss the status of the simulation study of the MANX in this document.

  2. The US Muon Accelerator Program (MAP)

    SciTech Connect

    Bross, Alan D.; /Fermilab

    2010-12-01

    The US Department of Energy Office of High Energy Physics has recently approved a Muon Accelerator Program (MAP). The primary goal of this effort is to deliver a Design Feasibility Study for a Muon Collider after a 7 year R&D program. This paper presents a brief physics motivation for, and the description of, a Muon Collider facility and then gives an overview of the program. I will then describe in some detail the primary components of the effort.

  3. Materials science with muon spin rotation

    NASA Technical Reports Server (NTRS)

    1988-01-01

    During this reporting period, the focus of activity in the Materials Science with Muon Spin Rotation (MSMSR) program was muon spin rotation studies of superconducting materials, in particular the high critical temperature and heavy-fermion materials. Apart from these studies, work was continued on the analysis of muon motion in metal hydrides. Results of these experiments are described in six papers included as appendices.

  4. Question of Lorentz violation in muon decay

    NASA Astrophysics Data System (ADS)

    Noordmans, J. P.; Onderwater, C. J. G.; Wilschut, H. W.; Timmermans, R. G. E.

    2016-06-01

    Possibilities to test the Lorentz invariance of the weak interaction in muon decay are considered. We derive the direction-dependent muon-decay rate with a general Lorentz-violating addition to the W -boson propagator. We discuss measurements of the directional and boost dependence of the Michel parameters and of the muon lifetime as a function of absolute velocity. The total muon-decay rate in the Lorentz-violating standard model extension is addressed. Suggestions are made for dedicated (re)analyses of the pertinent data and for future experiments.

  5. Magnets for Muon 6D Cooling Channels

    SciTech Connect

    Johnson, Rolland; Flanagan, Gene

    2014-09-10

    The Helical Cooling Channel (HCC), an innovative technique for six-dimensional (6D) cooling of muon beams using a continuous absorber inside superconducting magnets, has shown considerable promise based on analytic and simulation studies. The implementation of this revolutionary method of muon cooling requires high field superconducting magnets that provide superimposed solenoid, helical dipole, and helical quadrupole fields. Novel magnet design concepts are required to provide HCC magnet systems with the desired fields for 6D muon beam cooling. New designs feature simple coil configurations that produce these complex fields with the required characteristics, where new high field conductor materials are particularly advantageous. The object of the program was to develop designs and construction methods for HCC magnets and design a magnet system for a 6D muon beam cooling channel. If successful the program would develop the magnet technologies needed to create bright muon beams for many applications ranging from scientific accelerators and storage rings to beams to study material properties and new sources of energy. Examples of these applications include energy frontier muon colliders, Higgs and neutrino factories, stopping muon beams for studies of rare fundamental interactions and muon catalyzed fusion, and muon sources for cargo screening for homeland security.

  6. Neutrino induced muons in Soudan 2.

    SciTech Connect

    DeMuth, D. M.; Soudan 2 Collaboration

    1999-06-23

    The neutrino-induced muon rate underground has been measured at Soudan 2. To discriminate from the intense background of atmospheric muons we consider only the through-going muons which originate from horizontal direction ({minus}0.14 < cos{theta} < 0.14). We calculate the horizontal, neutrino-induced muon rate at Soudan 2 from an exposure of 1.23 x 10{sup 8} s as {Phi}{sub {nu}{mu}} = (3.45 {+-} 0.52 {+-} 0.61) x 10{sup {minus}13} (cm{sup 2} sr s){sup {minus}1}.

  7. The MANX Muon Cooling Experiment Detection System

    SciTech Connect

    Kahn, S. A.; Abrams, R. J.; Ankenbrandt, C.; Cummings, M. A. C.; Johnson, R. P.; Robertsa, T. J.; Yoneharab, K.

    2010-03-30

    The MANX experiment is being proposed to demonstrate the reduction of 6D muon phase space emittance, using a continuous liquid absorber to provide ionization cooling in a helical solenoid magnetic channel. The experiment involves the construction of a two-period-long helical cooling channel (HCC) to reduce the muon invariant emittance by a factor of two. The HCC would replace the current cooling section of the MICE experiment now being set up at the Rutherford Appleton Laboratory. The MANX experiment would use the existing MICE spectrometers and muon beam line. We discuss the placement of detection planes to optimize the muon track resolution.

  8. Le Point sur la Pharmacologie des Agents Anesthesiques Chez le Brule Grave

    PubMed Central

    Siah, S.; Ababou, K.; Benziane, H.; El Jaoudi; Bensghir, M.; Bakali, H.; El Wali, A.; Ihrai, I.; Drissi, N.K.

    2008-01-01

    Summary La pharmacologie des agents anesthésiques chez le brûlé est variable et imprévisible. Dans les premières 48 h, il y a une hypovolémie avec chute du débit cardiaque et des fuites plasmatiques. Après 48 h, il y a une hypervolémie avec augmentation du débit cardiaque, hypermétabolisme et la clearance des médicaments est augmentée. Parmi les facteurs de déséquilibre, on retrouve les variations des protéines plasmatiques. Deux protéines sont importantes chez le brûlé grave : l'albumine et l'alpha 1- glycoprotéine. Leur taux varie beaucoup au cours de l'évolution de la brûlure. Les agents anesthésiques dont la liaison avec ces deux protéines est prédominante verront leur pharmacocinétique modifiée. L'anesthésiste-réanimateur du service des brûlés va maîtriser ces notions pharmacologiques pour utiliser à bon escient les agents anesthésiques. PMID:21991108

  9. Modelisations des effets de surface sur les jets horizontaux subsoniques d'hydrogene et de methane

    NASA Astrophysics Data System (ADS)

    Gomez, Luis Fernando

    Le developpement des codes et de normes bases sur une methodologie scientifique requiert la capacite de predire l'etendue inflammable de deversements gazeux d'hydrogene sous differentes conditions. Des etudes anterieures ont deja etabli des modeles bases sur les lois de conservation de la mecanique des fluides basees sur des correlations experimentales qui permettent de predire la decroissance de la concentration et de la vitesse d'un gaz le long de l'axe d'un jet libre vertical. Cette etude s'interesse aux effets de proximite a une surface horizontale parallele sur un jet turbulent. Nous nous interessons a son impact sur l'etendue du champ de la concentration et sur l'enveloppe inflammable en particulier. Cette etude est comparative : l'hydrogene est compare au methane. Ceci permet de degager l'influence des effets de difference de la densite sur le comportement du jet, et de comparer le comportement de l'hydrogene aux correlations experimentales, qui ont ete essentiellement etablies pour le methane. Un modele decrivant l'evolution spatio-temporelle du champ de concentration du gaz dilue est propose, base sur la mecanique des fluides computationnelle. Cette approche permet de varier systematiquement les conditions aux frontieres (proximite du jet a la surface, par exemple) et de connaitre en detail les proprietes de l'ecoulement. Le modele est implemente dans le code de simulations par volumes finis de FLUENT. Les resultats des simulations sont compares avec les lois de similitudes decoulant de la theorie des jets d'ecoulements turbulents libres ainsi qu'avec les resultats experimentaux disponibles. L'effet de la difference des masses molaires des constituantes du jet et des constituantes du milieu de dispersion est egalement etudie dans le contexte du comportement d'echelle de la region developpee du jet.

  10. Analyse des facteurs prédictifs de malignité des goitres nodulaires : à propos de 500 cas

    PubMed Central

    Bouaity, Brahim; Darouassi, Youssef; Chihani, Mehdi; Touati, Mohamed Mliha; Ammar, Haddou

    2016-01-01

    Les nodules thyroïdiens sont très fréquents et moins de 10% d'entre eux sont malin. Ils posent un véritable problème diagnostique et thérapeutique surtout par rapport à leur nature bénigne ou maligne. L’étude de certains facteurs cliniques et paracliniques de présomption de malignité permet de bien codifier la stratégie thérapeutique. Le but de ce travail est d’étudier les facteurs prédictifs de malignité des goitres nodulaires et comparer nos résultats à ceux de la littérature. Il s'agit d'une étude rétrospective à propos de 500 cas de goitres nodulaires opérés au service d'Oto-rhino-laryngologie (ORL) et Chirurgie cervico-faciale (CCF) de l'hôpital militaire Avicenne de Marrakech entre 2006 et 2012. Le pourcentage de cancers a été de 6,8%. L’âge moyen de nos patients était de 46 ans, avec une sex-ratio de 5 (F/H). A la palpation cervicale; le caractère dure du nodule a été constaté dans 94,4% des cas de cancer, avec des limites irrégulières dans 64,70% des cas de cancer. Trois nodules étaient fixes et ils étaient tous malins. Les adénopathies cervicales ont été constatées chez 8 malades dont 7 présentaient des cancers. A l’échographie, 61,8% des nodules malins présentaient un aspect hypoéchogène, avec des contours flous dans 88,24% des cas. La vascularisation intra nodulaire était présente dans 35,3% de ces cas des cancers avec des microcalcifications chez 55,9% d'entre eux. Le halo hypoéchogene périnodulaire était incomplet dans 73,5% des cas de cancer. Nos patients étaient en euthyroïdie dans 84,6% des cas. Les facteurs prédictifs de malignité d'un goitre nodulaire, étaient donc dans notre étude d'abord cliniques: l’âge supérieur à 60 ans, la consistance dure du nodule, sa fixité, son caractère irrégulier et mal limité à la palpation, ainsi que la présence d'adénopathie(s) cervicale(s) à l'examen; et échographiques: le caractère hypoéchogène, les limites floues, la présence de

  11. Hadronic interactions and EAS muon pseudorapidities investigated with the Muon Tracking Detector in KASCADE-Grande

    NASA Astrophysics Data System (ADS)

    Zabierowski, J.; Apel, W. D.; Arteaga, J. C.; Badea, F.; Bekk, K.; Bertaina, M.; Blümer, H.; Bozdog, H.; Brancus, I. M.; Brüggemann, M.; Buchholz, P.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Finger, M.; Fuhrmann, D.; Ghia, P. L.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Klages, H. O.; Kolotaev, Y.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Nehls, S.; Oehlschläger, J.; Ostapchenko, S.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schröder, F.; Sima, O.; Stümpert, M.; Toma, G.; Trinchero, G. C.; Ulrich, H.; van Buren, J.; Walkowiak, W.; Weindl, A.; Wochele, J.; Wommer, M.; KASCADE-Grande Collaboration

    2009-12-01

    The Muon Tracking Detector in the KASCADE-Grande EAS experiment allows the precise measurement of shower muon directions up to 700 m distance from the shower center. This directional information is used to study the pseudorapidity of muons in EAS, closely related to the pseudorapidity of their parent mesons. Moreover, the mean value of muon pseudorapidity in a registered shower reflects the longitudinal development of its hadronic component. All of this makes it a good tool for testing hadronic interaction models. The possibilities of such tests given by the KASCADE-Grande experimental setup are discussed and an example of the obtained muon pseudorapidity spectrum is shown.

  12. First results of the cosmic ray muon variation study by means of the scintillation muon hodoscope

    NASA Astrophysics Data System (ADS)

    Ampilogov, N. V.; Astapov, I. I.; Barbashina, N. S.; Borog, V. V.; Dmitrieva, A. N.; Kovylyaeva, A. A.; Kompaniets, K. G.; Petrukhin, A. A.; Shutenko, V. V.; Yashin, I. I.

    2016-02-01

    The new scintillation muon hodoscope to study cosmic ray muon flux variations was created in MEPhI. The basic characteristics of the hodoscope (sensitivity area, precision of the muon track reconstruction, ‘live’ time etc.) are comparable with other hodoscopes (TEMP and URAGAN) of MEPhI. Modular design is a distinctive feature of the detector, supplying relativity easy transportability, and low maintenance requirements give a possibility of a long-term autonomic operation. First results of the cosmic ray muon variation study by means of the scintillation muon hodoscope are presented and discussed.

  13. Imaging the Subsurface with Upgoing Muons

    NASA Astrophysics Data System (ADS)

    Bonal, N.; Preston, L. A.; Schwellenbach, D.; Dreesen, W.; Green, A.

    2014-12-01

    We assess the feasibility of imaging the subsurface using upgoing muons. Traditional muon imaging focuses on more-prevalent downgoing muons. Muons are subatomic particles capable of penetrating the earth's crust several kilometers. Downgoing muons have been used to image the Pyramid of Khafre of Giza, various volcanoes, and smaller targets like cargo. Unfortunately, utilizing downgoing muons requires below-target detectors. For aboveground objects like a volcano, the detector is placed at the volcano's base and the top portion of the volcano is imaged. For underground targets like tunnels, the detector would have to be placed below the tunnel in a deeper tunnel or adjacent borehole, which can be costly and impractical for some locations. Additionally, detecting and characterizing subsurface features like voids from tunnels can be difficult. Typical characterization methods like sonar, seismic, and ground penetrating radar have shown mixed success. Voids have a marked density contrast with surrounding materials, so using methods sensitive to density variations would be ideal. High-energy cosmic ray muons are more sensitive to density variation than other phenomena, including gravity. Their absorption rate depends on the density of the materials through which they pass. Measurements of muon flux rate at differing directions provide density variations of the materials between the muon source (cosmic rays and neutrino interactions) and detector, much like a CAT scan. Currently, tomography using downgoing muons can resolve features to the sub-meter scale. We present results of exploratory work, which demonstrates that upgoing muon fluxes appear sufficient to achieve target detection within a few months. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  14. Les effets des interfaces sur les proprietes magnetiques et de transport des multicouches nickel/iron et cobalt/silver

    NASA Astrophysics Data System (ADS)

    Veres, Teodor

    Cette these est consacree a l'etude de l'evolution structurale des proprietes magnetiques et de transport des multicouches Ni/Fe et nanostructures a base de Co et de l'Ag. Dans une premiere partie, essentiellement bibliographique, nous introduisons quelques concepts de base relies aux proprietes magnetiques et de transport des multicouches metalliques. Ensuite, nous presentons une breve description des methodes d'analyse des resultats. La deuxieme partie est consacree a l'etude des proprietes magnetiques et de transport des multicouches ferromagnetiques/ferromagnetiques Ni/Fe. Nous montrerons qu'une interpretation coherente de ces proprietes necessite la prise en consideration des effets des interfaces. Nous nous attacherons a mettre en evidence, a evaluer et a etudier les effets de ces interfaces ainsi que leur evolution, et ce, suite a des traitements thermiques tel que le depot a temperature elevee et l'irradiation ionique. Les analyses correlees de la structure et de la magnetoresistance nous permettront d'emettre des conclusions sur l'influence des couches tampons entre l'interface et le substrat ainsi qu'entre les couches elles-memes sur le comportement magnetique des couches F/F. La troisieme partie est consacree aux systemes a Magneto-Resistance Geante (MRG) a base de Co et Ag. Nous allons etudier l'evolution de la microstructure suite a l'irradiation avec des ions Si+ ayant une energie de 1 MeV, ainsi que les effets de ces changements sur le comportement magnetique. Cette partie debutera par l'analyse des proprietes d'une multicouche hybride, intermediaire entre les multicouches et les materiaux granulaires. Nous analyserons a l'aide des mesures de diffraction, de relaxation superparamagnetique et de magnetoresistance, les evolutions structurales produites par l'irradiation ionique. Nous etablirons des modeles qui nous aideront a interpreter les resultats pour une serie des multicouches qui couvrent un large eventail de differents comportements magnetiques

  15. A plastic scintillator-based muon tomography system with an integrated muon spectrometer

    NASA Astrophysics Data System (ADS)

    Anghel, V.; Armitage, J.; Baig, F.; Boniface, K.; Boudjemline, K.; Bueno, J.; Charles, E.; Drouin, P.-L.; Erlandson, A.; Gallant, G.; Gazit, R.; Godin, D.; Golovko, V. V.; Howard, C.; Hydomako, R.; Jewett, C.; Jonkmans, G.; Liu, Z.; Robichaud, A.; Stocki, T. J.; Thompson, M.; Waller, D.

    2015-10-01

    A muon scattering tomography system which uses extruded plastic scintillator bars for muon tracking and a dedicated muon spectrometer that measures scattering through steel slabs has been constructed and successfully tested. The atmospheric muon detection efficiency is measured to be 97% per plane on average and the average intrinsic hit resolution is 2.5 mm. In addition to creating a variety of three-dimensional images of objects of interest, a quantitative study has been carried out to investigate the impact of including muon momentum measurements when attempting to detect high-density, high-Z material. As expected, the addition of momentum information improves the performance of the system. For a fixed data-taking time of 60 s and a fixed false positive fraction, the probability to detect a target increases when momentum information is used. This is the first demonstration of the use of muon momentum information from dedicated spectrometer measurements in muon scattering tomography.

  16. La valgisation tibiale par addition d'ouverture interne avec comblement cimenté dans la gonarthrose fémorotibiale médiale sur 38 genu-varum

    PubMed Central

    Mahraoui, Mohamed Amine; Abouchane, Merouane; El Andaloussi, Yassir; Haddoun, Ahmed Reda; Nechad, Mohamed

    2015-01-01

    Le genu varum sur gonarthrose fémorotibiale interne est une pathologie en nette recrudescence dans notre pays, affectant spécialement les femmes âgées et hautement invalidante chez l'adulte jeune; Souvent, elle pose un problème d'indication et de choix thérapeutique d'ordre multifactoriel. L'ostéotomie tibiale de valgisation par ouverture interne est une technique de référence, bien connue depuis longtemps et d'efficacité validée à court, moyen et long terme, et constitue un outil thérapeutique de choix et d'apport marqué, notamment pour les sujets jeunes actifs avec gonarthrose débutante. Par ailleurs, cette technique peut voir ses indications s’élargir au dépend de l’âge et du stade évolutif. Le but de notre travail est d’évaluer les résultats anatomiques et fonctionnels de notre technique d'ostéotomie tibiale de valgisation avec comblement cimenté chez l'adulte jeune de plus de 40 ans et de préciser les facteurs pronostiques qui régissent ces résultats. Ce travail propose à travers une étude rétrospectivement menée à propos de 38 genoux opérés chez 28 patients de dresser un bilan épidémiologique, clinique, et radiologique afin d’évaluer les résultats anatomiques et fonctionnels immédiats et à distance avec un recul minimum de 2 ans, de l'ostéotomie tibiale de valgisation avec comblement cimenté. Les 28 cas ont été revus à un recul moyen de 3,7 ans avec des extrêmes entre 2 et 9 ans, l’âge moyen de nos malades était de 52 ans avec des extrêmes de 40 à 67 ans, le sexe féminin était prédominant (64%). Le genu varum était primitif dans 20 cas (71,4%), et secondaire dans 8 cas (28,5%). Les stades I et II d'Ahlback constituaient la majorité des cas de l'arthrose fémoro-tibiale (94,7%). La déviation angulaire globale moyenne était de 11,3° avec des extrêmes de 8,5° à 18°. Les résultats évalués selon le protocole du groupe Guépar étaient excellents et très bons dans 86% des cas, et moyens et

  17. HIGH ENERGY PHYSICS POTENTIAL AT MUON COLLIDERS

    SciTech Connect

    PARSA,Z.

    2000-04-07

    In this paper, high energy physics possibilities and future colliders are discussed. The {mu}{sup +} {mu}{sup {minus}} collider and experiments with high intensity muon beams as the stepping phase towards building Higher Energy Muon Colliders (HEMC) are briefly reviewed and encouraged.

  18. Muon radiography for exploration of Mars geology

    NASA Astrophysics Data System (ADS)

    Kedar, S.; Tanaka, H. K. M.; Naudet, C. J.; Jones, C. E.; Plaut, J. P.; Webb, F. H.

    2013-06-01

    Muon radiography is a technique that uses naturally occurring showers of muons (penetrating particles generated by cosmic rays) to image the interior of large-scale geological structures in much the same way as standard X-ray radiography is used to image the interior of smaller objects. Recent developments and application of the technique to terrestrial volcanoes have demonstrated that a low-power, passive muon detector can peer deep into geological structures up to several kilometers in size, and provide crisp density profile images of their interior at ten meter scale resolution. Preliminary estimates of muon production on Mars indicate that the near horizontal Martian muon flux, which could be used for muon radiography, is as strong or stronger than that on Earth, making the technique suitable for exploration of numerous high priority geological targets on Mars. The high spatial resolution of muon radiography also makes the technique particularly suited for the discovery and delineation of Martian caverns, the most likely planetary environment for biological activity. As a passive imaging technique, muon radiography uses the perpetually present background cosmic ray radiation as the energy source for probing the interior of structures from the surface of the planet. The passive nature of the measurements provides an opportunity for a low power and low data rate instrument for planetary exploration that could operate as a scientifically valuable primary or secondary instrument in a variety of settings, with minimal impact on the mission's other instruments and operation.

  19. ACCELERATION FOR A HIGH ENERGY MUON COLLIDER

    SciTech Connect

    BERG,J.S

    2000-04-07

    The authors describe a method for designing the acceleration systems for a muon collider, with particular application and examples for a high energy muon collider. This paper primarily concentrates on design considerations coming from longitudinal motion, but some transverse issues are briefly discussed.

  20. Neutrino physics at a muon collider

    SciTech Connect

    King, B.J.

    1998-02-01

    This paper gives an overview of the neutrino physics possibilities at a future muon storage ring, which can be either a muon collider ring or a ring dedicated to neutrino physics that uses muon collider technology to store large muon currents. After a general characterization of the neutrino beam and its interactions, some crude quantitative estimates are given for the physics performance of a muon ring neutrino experiment (MURINE) consisting of a high rate, high performance neutrino detector at a 250 GeV muon collider storage ring. The paper is organized as follows. The next section describes neutrino production from a muon storage rings and gives expressions for event rates in general purpose and long baseline detectors. This is followed by a section outlining a serious design constraint for muon storage rings: the need to limit the radiation levels produced by the neutrino beam. The following two sections describe a general purpose detector and the experimental reconstruction of interactions in the neutrino target then, finally, the physics capabilities of a MURINE are surveyed.

  1. Polarization Effects at a Muon Collider

    SciTech Connect

    Parsa, Z.

    1998-11-01

    For Muon Colliders, Polarization will be a useful tool if high polarization is achievable with little luminosity loss. Formulation and effects of beam polarization and luminosity including polarization effects in Higgs resonance studies are discussed for improving precision measurements and Higgs resonance ''discovery'' capability e.g. at the First Muon Collider (FMC).

  2. The OPAL muon barrel detector

    NASA Astrophysics Data System (ADS)

    Akers, R. J.; Allison, J.; Ashton, P.; Bahan, G. A.; Baines, J. T. M.; Banks, J. N.; Barlow, R. J.; Barnett, S.; Beeston, C.; Chrin, J. T. M.; Clowes, S. G.; Davies, O. W.; Duerdoth, I. P.; Hinde, P. S.; Hughes-Jones, R. E.; Lafferty, G. D.; Loebinger, F. K.; Macbeth, A. A.; McGowan, R. F.; Moss, M. W.; Murphy, P. G.; Nijjhar, B.; O'Dowd, A. J. P.; Pawley, S. J.; Phillips, P. D.; Richards, G. E.; Skillman, A.; Stephens, K.; Tresillian, N. J.; Wood, N. C.; Wyatt, T. R.

    1995-02-01

    The barrel part of the OPAL muon detector consists of 110 drift chambers forming four layers outside the hadron absorber. Each chamber covers an area of 1.2 m by up to 10.4 m and has two cells with wires parallel to the beam and a drift distance of 297 mm. A detailed description of the design, construction, operation and performance of the sub-detector is given. The system has been operating successfully since the start of LEP in 1989.

  3. Detector Background at Muon Colliders

    SciTech Connect

    Mokhov, N.V.; Striganov, S.I.; /Fermilab

    2011-09-01

    Physics goals of a Muon Collider (MC) can only be reached with appropriate design of the ring, interaction region (IR), high-field superconducting magnets, machine-detector interface (MDI) and detector. Results of the most recent realistic simulation studies are presented for a 1.5-TeV MC. It is shown that appropriately designed IR and MDI with sophisticated shielding in the detector have a potential to substantially suppress the background rates in the MC detector. The main characteristics of backgrounds are studied.

  4. Tous les chemins menent a Rome avec des proverbes (All Roads Lead to Rome with Proverbs).

    ERIC Educational Resources Information Center

    Lamy, Yves

    1986-01-01

    Suggests activities for teaching proverbs, an important part of the cultural education of second language learners. Activities include identifying proverbs in common discourse, creating skits and cartoons or pictures based on them, creating puzzles, inventing original proverbs, and analyzing their practical value. (MSE)

  5. Une lecon de francais avec des jeux electroniques (A French Lesson with Electronic Games).

    ERIC Educational Resources Information Center

    Malandain, Jean-Louis

    1996-01-01

    Electronic games are proposed as a means for encouraging students of French to learn and use the language while solving problems. A computerized card game and mine-removal game are offered as illustration of the language skills and vocabulary that can be developed and the appeal that such exercises can have for students. (MSE)

  6. Apprendre par le dialogue : le cas des pharmaciens d'officine en interaction avec leurs clients

    NASA Astrophysics Data System (ADS)

    Cohen-Scali, Valérie; Ramsamy-Prat, Padma

    2015-12-01

    Learning through dialogue: the case of retail pharmacists' interactions with their customers - This article seeks to highlight certain identity processes that are mobilized through dialogue in the workplace and that promote learning (or information gathering) in this context. These processes are studied in the population of retail pharmacists, much of whose work centres on interactions with customers. Dutch psychologist Hubert Hermans' theory of the dialogical self is used as a theoretical framework. The main hypothesis developed in the article is that to understand the problems of the customers who come into their pharmacies and adapt to their requests, pharmacists must adopt a series of I positions in their dialogues with them. French pharmacists in Paris and the Paris region were observed and interviewed. The four dialogue extracts studied here underline the diversity of I-positions implemented in pharmacist-customer dialogues. The diversity of registers that pharmacists are able to deploy in their interactions appears to be inherent to their professionalism and a necessary aspect of their work. These results open up perspectives for further research into the association of workplace learning and identity transformation.

  7. Structure electronique de nanorubans de graphene avec des contacts metalliques: Une etude ab initio

    NASA Astrophysics Data System (ADS)

    Archambault, Chloe

    Graphene, a graphite monolayer presenting novel exciting properties, has attracted much attention recently in the scientific community as well as in the high-technology industry. In electronics, nanoribbons -- narrow strips of graphene which happen to be semiconducting-- could possibly allow further miniaturization of electronic devices such as transistors because of their atomic thickness. On the other hand, once making devices, the problem of metallic contacts, which can have critical impact at the nanoscopic scale, cannot be evaded. For example, metal induced gap states may short-circuit very short devices. With this in mind, the interaction of gold, palladium and titanium contacts with finite size graphene nanoribbons has been studied using ab initio density functional theory calculations. This theoretical approach made it possible to study separately and then conjugate four important aspects of the metal-ribbon interaction: bonding, charge transfer, electrostatics and metal induced gap states. Another goal of this project was to study size effects related to the ribbons' dimensions and to estimate the minimal channel length necessary for a device to operate as expected without the unwanted effect of induced gap states. Aside from the high precision achieved, these calculations stand out from earlier studies because they take into account finite size effects which often prevail in small ribbons. Using this model for the metal-nanoribbon junction, it was shown that, as for two-dimensional graphene, the bonding between a ribbon and a metal can be of two types depending on the electronic configuration of the metal. In the first case, physisorption, weak bonding resulting in a large separation distance between ribbon and electrode, is illustrated by the gold contact. On the other hand, titanium, because of its high density of states at the Fermi level, binds more strongly with graphene nanoribbons. This chemisorption is characterized by strong hybridization between the metal and the ribbon's orbitals. This leads to the apparition of intense evanescent gap states in the ribbon. As for palladium, it represents an intermediate case showing some but not as much hybridization. For all three metals, right under the contact, we observe a net decrease of electron density in the ribbon in favour of the contact. Effectively, any kind of bonding is generally associated with charge transfer necessary to balance the work function difference. As expected, a metal with a large work function such as gold and palladium tends to attract electrons. However, this behaviour is surprising from titane whose work function is much smaller. This can only be explained by considering the large hybridization of the ribbon's orbitals. Moreover, the charge transfer is not restricted to the area under the contact as an evanescent charge can also be observed in the channel. This charge results from the occupation of metal induced gap states and its sign depends on the position of the charge neutrality point. The calculations presented don't take into account the effect of temperature. Nevertheless, the position of the Fermi level relative to the ribbon's bands suggests that at non-zero temperature, gold and palladium would p dope the graphene nanoribbons while titanium would have the opposite effect. The charge redistribution in the junction generates a molecular-sized dipole which is responsible for the slowly varying three-dimensional potential profile, a particularity of low dimensional systems. A potential barrier thus appears at the interface and controls band curvature in the device, but it can also constitute an obstacle to efficient charge injection. The intimate relation between the titanium contact and the ribbons seems to maximize screening and reduce considerably the height of the barrier, which could turn out to be beneficial. Finally, metal induced gap states slowly decaying in the channel have been observed directly in graphene nanoribbons for the first time. Their characteristic evanescent shape is clearly distinguishable. The extent of the gap states was measured to be on the order of a nanometer. It depends mostly on the ribbon's bandgap which varies both with its length and width. The bandgap, which can easily be measured experimentally, could thus be a useful tool to predict the penetration of gap states, a must-have information in order to limit the undesired effect of gap states since it sets for a device the minimal channel length (˜1-2 nm). In summary, these theoretical results could be used as a guideline in the conception of electronic devices made of graphene nanoribbons in which doping and potential profile need to be optimized while making sure that metal induced gap states do not compromise normal operation.

  8. Reverse Emittance Exchange for Muon Colliders

    SciTech Connect

    V. Ivanov, A. Afanasev, C.M. Ankenbrandt, R.P. Johnson, G.M. Wang, S.A. Bogacz, Y.S. Derbenev

    2009-05-01

    Muon collider luminosity depends on the number of muons in the storage ring and on the transverse size of the beams in collision. Ionization cooling as it is currently envisioned will not cool the beam sizes sufficiently well to provide adequate luminosity without large muon intensities. Six-dimensional cooling schemes will reduce the longitudinal emittance of a muon beam so that smaller high frequency RF cavities can be used for later stages of cooling and for acceleration. However, the bunch length at collision energy is then shorter than needed to match the interaction region beta function. New ideas to shrink transverse beam dimensions by lengthening each bunch will help achieve high luminosity in muon colliders. Analytic expressions for the reverse emittance exchange mechanism were derived, including a new resonant method of beam focusing.

  9. Recirculating Linac Accelerators For Future Muon Facilities

    SciTech Connect

    Yves Roblin, Alex Bogacz, Vasiliy Morozov, Kevin Beard

    2012-04-01

    Neutrino Factories (NF) and Muon Colliders (MC) require rapid acceleration of shortlived muons to multi-GeV and TeV energies. A Recirculating Linear Accelerator (RLA) that uses superconducting RF structures can provide exceptionally fast and economical acceleration to the extent that the focusing range of the RLA quadrupoles allows each muon to pass several times through each high-gradient cavity. A new concept of rapidly changing the strength of the RLA focusing quadrupoles as the muons gain energy is being developed to increase the number of passes that each muon will make in the RF cavities, leading to greater cost effectiveness. We discuss the optics and technical requirements for RLA designs, using RF cavities capable of simultaneous acceleration of both m+ and m- species. The design will include the optics for the multi-pass linac and droplet-shaped return arcs.

  10. Can 250 fusions per muon be achieved

    SciTech Connect

    Jones, S.E.

    1987-01-01

    Nuclear fusion of hydrogen isotopes can be induced by negative muons ( ) in reactions such as: + d + t + n + . This reaction is analagous to the nuclear fusion reaction achieved in stars in which hydrogen isotopes (such as deuterium, d, and tritium, t) at very high temperatures first penetrate the Coulomb repulsive barrier and then fuse together to produce an alpha particle ( ) and a neutron (n), releasing energy. The muon in general reappears after inducing fusion so that the reaction can be repeated many (N) times. Thus, the muon may serve as an effective catalyst for nuclear fusion. Muon-catalozed fusion is unique in that it proceeds rapidly in deuterium-tritium mixtures at relatively cold temperatures, e.g., room temperature. The need for plasma temperatures to initiate fusion is overcome by the presence of the muon.

  11. Cold fusion catalyzed by muons and electrons

    SciTech Connect

    Kulsrud, R.M.

    1990-10-01

    Two alternative methods have been suggested to produce fusion power at low temperature. The first, muon catalyzed fusion or MCF, uses muons to spontaneously catalyze fusion through the muon mesomolecule formation. Unfortunately, this method fails to generate enough fusion energy to supply the muons, by a factor of about ten. The physics of MCF is discussed, and a possible approach to increasing the number of MCF fusions generated by each muon is mentioned. The second method, which has become known as Cold Fusion,'' involves catalysis by electrons in electrolytic cells. The physics of this process, if it exists, is more mysterious than MCF. However, it now appears to be an artifact, the claims for its reality resting largely on experimental errors occurring in rather delicate experiments. However, a very low level of such fusion claimed by Jones may be real. Experiments in cold fusion will also be discussed.

  12. La structure de Jordan des matrices de transfert des modeles de boucles et la relation avec les hamiltoniens XXZ

    NASA Astrophysics Data System (ADS)

    Morin-Duchesne, Alexi

    Lattice models such as percolation, the Ising model and the Potts model are useful for the description of phase transitions in two dimensions. Finding analytical solutions is done by calculating the partition function, which in turn requires finding eigenvalues of transfer matrices. At the critical point, the two dimensional statistical models are invariant under conformal transformations and the construction of rational conformal field theories, as the continuum limit of these lattice models, allows one to compute the partition function at the critical point. Many researchers think however that the paradigm of rational conformal conformal field theories can be extended to include models with non diagonalizable transfer matrices. These models would then be described, in the scaling limit, by logarithmic conformal field theories and the representations of the Virasoro algebra coming into play would be indecomposable. We recall the construction of the double-row transfer matrix DN (λ, u) of the Fortuin-Kasteleyn model, seen as an element of the Temperley-Lieb algebra. This transfer matrix comes into play in physical theories through its representation in link modules (or standard modules). The vector space on which this representation acts decomposes into sectors labelled by a physical parameter d, the number of defects, which remains constant or decreases in the link representations. This thesis is devoted to the identification of the Jordan structure of DN(λ, u) in the link representations. The parameter β = 2 cos λ = -(q + q-1) fixes the theory : for instance β = 1 for percolation and 2 for the Ising model. On the geometry of the strip with open boundary conditions, we show that DN(λ, u) has the same Jordan blocks as its highest Fourier coefficient, FN. We study the non-diagonalizability of FN through the divergences of some of the eigenstates of ρ(F N) that appear at the critical values of λ. The Jordan cells we find in ρ(DN(λ, u)) have rank 2 and couple sectors d and d' when specific constraints on λ, d, d' and N are satisfied. For the model of critical dense polymers (β = 0) on the strip, the eigenvalues of ρ(DN(λ, u)) were known, but their degeneracies only conjectured. By constructing an isomorphism between the link modules on the strip and a subspace of spin modules of the XXZ model at q = i, we prove this conjecture. We also show that the restriction of the Hamiltonian to any sector d is diagonalizable, and that the XX Hamiltonian has rank 2 Jordan cells when N is even. Finally, we study the Jordan structure of the transfer matrix T N(λ, ν) for periodic boundary conditions. When λ = πa/b and a, b ∈ Z× , the matrix TN(λ, ν) has Jordan blocks between sectors, but also within sectors. The approach using FN admits a generalization to the present case and allows us to probe the Jordan cells that tie different sectors. The rank of these cells exceeds 2 in some cases and can grow indefinitely with N. For the Jordan blocks within a sector, we show that the link modules on the cylinder and the XXZ spin modules are isomorphic except for specific curves in the (q, ν) plane. By using the behavior of the transformation ĩd N in a neighborhood of the critical values (qc, ν c), we explicitly build Jordan partners of rank 2 and discuss the existence of Jordan cells with higher rank. Keywords : phase transitions, Ising model, Potts model, Fortuin-Kasteleyn model, transfer matrix method, XXZ Hamiltonian, logarithmic conformal field theory, Jordan structure.

  13. Muon spin rotation research program

    NASA Technical Reports Server (NTRS)

    Stronach, C. E.

    1980-01-01

    Data from cyclotron experiments and room temperature studies of dilute iron alloys and iron crystals under strain were analyzed. The Fe(Mo) data indicate that the effect upon the contact hyperfine field in Fe due to the introduction of Mo is considerably less than that expected from pure dilution, and the muon (+) are attracted to the Mo impurity sites. There is a significant change in the interstitial magnetic field with Nb concentration. The Fe(Ti) data, for which precession could clearly be observed early only at 468K and above, show that the Ti impurities are attractive to muon (+), and the magnitude of B(hf) is reduced far beyond the amount expected from pure dilution. Changes in the intersitital magnetic field with the introduction of Cr, W, Ge, and Si are also discussed. When strained to the elastic limit, the interstitial magnetic field in Fe crystals is reduced by 33 gauss, and the relaxation rate of the precession signal increases by 47%.

  14. The muon collider (Sandro's snake)

    SciTech Connect

    Ruggiero, A.G.

    1992-01-01

    This paper describes a feasibility study for the design of a muon collider. Recognized the fact that the particle lifetime increases linearly with the energy, we have adopted a scheme where steps of cooling and acceleration are entwined. We have indeed found convenient to accelerate the beam as fast as possible to increase its chances of survival, and necessary to dilute the action of cooling throughout the entire accelerating process to make it more effective and affordable. All acceleration and cooling steps are executed in a single pass essentially along a curvilinear and open path. We do not believe it is possible to handle the beam otherwise in circular and closed rings, as it has been proposed in the past. The example shown in this paper describes a muon collider at the energy of 250 GeV per beam and a luminosity of 4 [times] 10[sup 28] cm[sup [minus]2]s[sup [minus]1]. We have adopted an extrapolation of the stochastic cooling method for the reduction of the beam emittance.

  15. Traitement des fractures des plateaux externes par vissage percutané assisté par arthroscopie

    PubMed Central

    Abouchane, Merouane; Belmoubarik, Amine; Benameur, Hamza; Haddoun, Ahmed Reda; Nechad, Mohammed

    2015-01-01

    Le but de notre étude est d'évaluer les résultats de fractures des plateaux tibiaux externes traitées par ostéosynthèse percutanée assistée par arthroscopie. Dix patients (8 hommes et 2 femmes) de 32 ans en moyenne ont subi cette intervention afin de réparer des fractures des plateaux tibiaux Schatzker I-III. Après avoir appliqué un garrot pneumatique, nous avons réduit et fixé la fracture au moyen de vis cannelées souschondrales. Lésions associées retrouvent deux lésions partielles du ménisque externe ont été retrouvé, traitées par résection partielle. Une orthèse de genou été de mise à but antalgique et protectrice pendant six semaines avec béquillage et interdiction de l'appui pour une durée de douze semaines avec reprise d'appui partiel au delà. La durée d'hospitalisation été d'une moyenne de cinq jours. La rééducation passive a été commence le lendemain de l'intervention et continuait dans chez un kinésithérapeute à la sortie du patient du service. Le suivi été à J7, J15, 1mois, 3mois, 6 mois puis tous les 6 mois. Neuf de nos patients ont été revu régulièrement sauf un perdu de vue. Le recul moyen de notre série été de 16 mois (10 et 24 mois). Le score de Lysholm a été utilisé pour évaluer les résultats cliniques chez nos neuf patients: excellent chez trois patients bons chez trois moyen chez un seul et mauvais chez deux patients. Tous nos neuf patients ont consolidé (figure 10 contrôle scopique d un article). Aucune gonarthrose n'a été note chez nos neuf patients due essentiellement au recul moyen faible de 16 mois. Le traitement des fractures des plateaux tibiaux externes assisté par arthroscopie produit des résultats satisfaisants et peut être accepté comme solution de rechange efficace au traitement des fractures des plateaux tibiaux causées par un choc de faible énergie. PMID:26587137

  16. Measurement of the muon beam direction and muon flux for the T2K neutrino experiment

    NASA Astrophysics Data System (ADS)

    Suzuki, K.; Aoki, S.; Ariga, A.; Ariga, T.; Bay, F.; Bronner, C.; Ereditato, A.; Friend, M.; Hartz, M.; Hiraki, T.; Ichikawa, A. K.; Ishida, T.; Ishii, T.; Juget, F.; Kikawa, T.; Kobayashi, T.; Kubo, H.; Matsuoka, K.; Maruyama, T.; Minamino, A.; Murakami, A.; Nakadaira, T.; Nakaya, T.; Nakayoshi, K.; Otani, M.; Oyama, Y.; Patel, N.; Pistillo, C.; Sakashita, K.; Sekiguchi, T.; Suzuki, S. Y.; Tada, S.; Yamada, Y.; Yamamoto, K.; Yokoyama, M.

    2015-05-01

    The Tokai-to-Kamioka (T2K) neutrino experiment measures neutrino oscillations by using an almost pure muon neutrino beam produced at the J-PARC accelerator facility. The T2K muon monitor was installed to measure the direction and stability of the muon beam which is produced in conjunction with the muon neutrino beam. The systematic error in the muon beam direction measurement was estimated, using data and MC simulation, to be 0.28 mrad. During beam operation, the proton beam has been controlled using measurements from the muon monitor and the direction of the neutrino beam has been tuned to within 0.3 mrad with respect to the designed beam-axis. In order to understand the muon beam properties, measurement of the absolute muon yield at the muon monitor was conducted with an emulsion detector. The number of muon tracks was measured to be (4.06± 0.05± 0.10)× 10^4cm^{-2} normalized with 4× 10^{11} protons on target with 250 kA horn operation. The result is in agreement with the prediction, which is corrected based on hadron production data.

  17. The program in muon and neutrino physics: Superbeams, cold muon beams, neutrino factory and the muon collider

    SciTech Connect

    R. Raja et al.

    2001-08-08

    The concept of a Muon Collider was first proposed by Budker [10] and by Skrinsky [11] in the 60s and early 70s. However, there was little substance to the concept until the idea of ionization cooling was developed by Skrinsky and Parkhomchuk [12]. The ionization cooling approach was expanded by Neufer [13] and then by Palmer [14], whose work led to the formation of the Neutrino Factory and Muon Collider Collaboration (MC) [3] in 1995. The concept of a neutrino source based on a pion storage ring was originally considered by Koshkarev [18]. However, the intensity of the muons created within the ring from pion decay was too low to provide a useful neutrino source. The Muon Collider concept provided a way to produce a very intense muon source. The physics potential of neutrino beams produced by muon storage rings was investigated by Geer in 1997 at a Fermilab workshop [19, 20] where it became evident that the neutrino beams produced by muon storage rings needed for the muon collider were exciting on their own merit. The neutrino factory concept quickly captured the imagination of the particle physics community, driven in large part by the exciting atmospheric neutrino deficit results from the SuperKamiokande experiment. As a result, the MC realized that a Neutrino Factory could be an important first step toward a Muon Collider and the physics that could be addressed by a Neutrino Factory was interesting in its own right. With this in mind, the MC has shifted its primary emphasis toward the issues relevant to a Neutrino Factory. There is also considerable international activity on Neutrino Factories, with international conferences held at Lyon in 1999, Monterey in 2000 [21], Tsukuba in 2001 [22], and another planned for London in 2002.

  18. Muons in minimum bias events from the first CMS data

    SciTech Connect

    Barbone, Lucia

    2010-12-22

    Muon signatures are extremely important in the challenging environment of collisions at the LHC. Understanding the observed muon yield from Standard Model processes is the first task for all analyses involving muons. Basic muon kinematical observables are presented for the first CMS data at {radical}(s) = 7 TeV and compared with Monte Carlo expectations. The muon sample composition is studied by using the MC truth in terms of muons from heavy flavours, muons from light hadron decays and hadron punch-through is studied from MC truth.

  19. Pion contamination in the MICE muon beam

    DOE PAGESBeta

    Adams, D.; Alekou, A.; Apollonio, M.; Asfandiyarov, R.; Barber, G.; Barclay, P.; de Bari, A.; Bayes, R.; Bayliss, V.; Bertoni, R.; et al

    2016-03-01

    Here, the international Muon Ionization Cooling Experiment (MICE) will perform a systematic investigation of ionization cooling with muon beams of momentum between 140 and 240\\,MeV/c at the Rutherford Appleton Laboratory ISIS facility. The measurement of ionization cooling in MICE relies on the selection of a pure sample of muons that traverse the experiment. To make this selection, the MICE Muon Beam is designed to deliver a beam of muons with less thanmore » $$\\sim$$1% contamination. To make the final muon selection, MICE employs a particle-identification (PID) system upstream and downstream of the cooling cell. The PID system includes time-of-flight hodoscopes, threshold-Cherenkov counters and calorimetry. The upper limit for the pion contamination measured in this paper is $$f_\\pi < 1.4\\%$$ at 90% C.L., including systematic uncertainties. Therefore, the MICE Muon Beam is able to meet the stringent pion-contamination requirements of the study of ionization cooling.« less

  20. Apport des moyens endoscopiques dans la dilatation des sténoses caustiques de l’œsophage

    PubMed Central

    Seydou, Togo; Abdoulaye, Ouattara Moussa; xing, Li; Zi, Sanogo Zimogo; sekou, Koumaré; Wen, Yang Shang; Ibrahim, Sankare; Sekou, Toure Cheik Ahmed; Boubacar, Maiga Ibrahim; Saye, Jacque; Jerome, Dakouo Dodino; Dantoumé, Toure Ousmane; Sadio, Yena

    2016-01-01

    Introduction Toutes les sténoses symptomatiques de l’œsophage peuvent être dilatées par voie endoscopique. Nous évaluons l'apport des moyens endoscopiques dans la prise en charge de la dilatation œsophagienne pour sténose caustique de l’œsophage (SCO) au Mali. Méthodes IL s'agissait d'une étude descriptive et prospective réalisée dans le service de chirurgie thoracique à l'hôpital du Mali. Au total 46 dossiers cliniques de patients on été enregistrés et subdivisés en 4 groupes en fonction de la topographie des lésions cicatricielles. Le nombre de cas d'assistance endoscopique réalisé a été déterminé afin de comprendre l'apport des moyens endoscopiques dans le succès de la dilatation des SCO. Pour les 2 différentes méthodes de dilatation utilisées, le résultat du traitement et le coût ont comparés. Résultats La FOGD a été utilisée dans 19 cas (41.30%) de dilatation avec la bougie de Savary Guillard et dans 47.82% des cas dans la dilatation de Lerut. La vidéo-laryngoscopie a été utilisé 58.69% des cas de dilatation à la bougie de Lerut. Le passage de guide métallique et / ou de fil-guide a été réalisée dans 39.13% avec la vidéo laryngoscopie et dans 58.68% avec la FOGD. Dans la comparaison des deux méthodes, il existe une différence significative dans la survenue des complications (p=0.04075), l'anesthésie générale (p=0.02287), l'accessibilité à la méthode (p=0.04805) et la mortalité (p=0.00402). Conclusion La SCO est une pathologie grave et sous évaluée au Mali. Les moyens endoscopiques contribuent considérablement au succès de la dilatation œsophagienne pour sténose caustique dans les différentes méthodes utilisées. PMID:27200129

  1. SNM detection by active muon interrogation

    SciTech Connect

    Jason, Andrew J; Miyadera, Haruo; Turchi, Peter J

    2010-01-01

    Muons are charged particles with mass between the electron and proton and can be produced indirectly through pion decay by interaction of a charged-particle beam with a target. There are several distinct features of the muon interaction with matter attractive as a probe for detection of SNM at moderate ranges. These include muon penetration of virtually any amount of material without significant nuclear interaction until stopped by ionization loss in a short distance. When stopped, high-energy penetrating x-rays (in the range of 6 MeV for uranium,) unique to isotopic composition are emitted in the capture process. The subsequent interaction with the nucleus produces additional radiation useful in assessing SNM presence. A focused muon beam can be transported through the atmosphere, at a range limited mainly by beam-size growth through scattering. A muonbeam intensity of > 10{sup 9} /second is required for efficient interrogation and, as in any other technique, dose limits are to be respected. To produce sufficient muons a high-energy (threshold {approx}140 MeV) high-intensity (<1 mA) proton or electron beam is needed implying the use of a linear accelerator to bombard a refractory target. The muon yield is fractionally small, with large angle and energy dispersion, so that efficient collection is necessary in all dimensions of phase space. To accomplish this Los Alamos has proposed a magnetic collection system followed by a unique linear accelerator that provides the requisite phase-space bunching and allows an energy sweep to successively stop muons throughout a large structure such as a sea-going vessel. A possible maritime application would entail fitting the high-gradient accelerators on a large ship with a helicopter-borne detection system. We will describe our experimental results for muon effects and particle collection along with our current design and program for a muon detection system.

  2. Cosmic muon detector using proportional chambers

    NASA Astrophysics Data System (ADS)

    Varga, Dezső; Gál, Zoltán; Hamar, Gergő; Sára Molnár, Janka; Oláh, Éva; Pázmándi, Péter

    2015-11-01

    A set of classical multi-wire proportional chambers was designed and constructed with the main purpose of efficient cosmic muon detection. These detectors are relatively simple to construct, and at the same time are low cost, making them ideal for educational purposes. The detector layers have efficiencies above 99% for minimum ionizing cosmic muons, and their position resolution is about 1 cm, that is, particle trajectories are clearly observable. Visualization of straight tracks is possible using an LED array, with the discriminated and latched signal driving the display. Due to the exceptional operating stability of the chambers, the design can also be used for cosmic muon telescopes.

  3. Imaging Fukushima Daiichi reactors with muons

    NASA Astrophysics Data System (ADS)

    Miyadera, Haruo; Borozdin, Konstantin N.; Greene, Steve J.; Lukić, Zarija; Masuda, Koji; Milner, Edward C.; Morris, Christopher L.; Perry, John O.

    2013-05-01

    A study of imaging the Fukushima Daiichi reactors with cosmic-ray muons to assess the damage to the reactors is presented. Muon scattering imaging has high sensitivity for detecting uranium fuel and debris even through thick concrete walls and a reactor pressure vessel. Technical demonstrations using a reactor mockup, detector radiation test at Fukushima Daiichi, and simulation studies have been carried out. These studies establish feasibility for the reactor imaging. A few months of measurement will reveal the spatial distribution of the reactor fuel. The muon scattering technique would be the best and probably the only way for Fukushima Daiichi to make this determination in the near future.

  4. Imaging Fukushima Daiichi reactors with muons

    SciTech Connect

    Miyadera, Haruo; Borozdin, Konstantin N.; Greene, Steve J.; Milner, Edward C.; Morris, Christopher L.; Lukic, Zarija; Masuda, Koji; Perry, John O.

    2013-05-15

    A study of imaging the Fukushima Daiichi reactors with cosmic-ray muons to assess the damage to the reactors is presented. Muon scattering imaging has high sensitivity for detecting uranium fuel and debris even through thick concrete walls and a reactor pressure vessel. Technical demonstrations using a reactor mockup, detector radiation test at Fukushima Daiichi, and simulation studies have been carried out. These studies establish feasibility for the reactor imaging. A few months of measurement will reveal the spatial distribution of the reactor fuel. The muon scattering technique would be the best and probably the only way for Fukushima Daiichi to make this determination in the near future.

  5. Systematic muon capture rates in PQRPA

    SciTech Connect

    Samana, A. R.; Sande, D.; Krmpotić, F.

    2015-05-15

    In this work we performed a systematic study of the inclusive muon capture rates for several nuclei with A < 60 using the Projected Random Quasi-particle Phase Approximation (PQRPA) as nuclear model, because it is the only RPA model that treats the Pauli Principle correctly. We reckon that the comparison between theory and data for the inclusive muon capture is not a fully satisfactory test on the nuclear model that is used. The exclusive muon transitions are more robust for such a purpose.

  6. Comparison des donnees simulees des capteurs de SPOT et landsat-D: Application a une region agricole

    NASA Astrophysics Data System (ADS)

    Saint, Gilbert; Podaire, Alain

    La modélisation de la luminance spectrale des objets observés en télédétection permet d'effectuer des simulations de différents capteurs à partir de données obtenues au moyen d'un scanneur DAEDALUS aéroporté : les qualités radiométrique et géométrique ont pu être évaluées par une comparaison avec des données Landsat réelles. L'analyse sur une zone agricole met surtout en évidence le rôle important de l'accroissement de la résolution.

  7. Des Moines.

    ERIC Educational Resources Information Center

    Gore, Deborah, Ed.

    1988-01-01

    This document, intended for elementary students, contains articles and activities designed to acquaint young people with the history of Des Moines, Iowa. The articles are short, and new or difficult words are highlighted and defined for young readers. "The Raccoon River Indian Agency" discusses the archeological exploration of the indian…

  8. TRANSPLANTATION EN MASSE DES ORGANES ABDOMINAUX

    PubMed Central

    STARZL, T.

    2010-01-01

    Les transplantations multi-organes, comprenant les blocs foie-duodénum-pancréas, foie-estomac-duodénum-pancréas, et foie-intestin sont réalisées avec un succés croissant Ces techniques et leurs combinaisons variées de transplantation monobloc ne sont pas de pratique courante. Les techniques de prélévement, de conservation et de soins post-opératoires sont décrites pour la transplantation multi-organes compléte ainsi que pour les variantes incomplétes. Le probléme particulier à ce type de transplantation est celui de la transplantation intestinale, c’est-à-dire la transplantation d’un organe à composante lymphoréticulaire complexe ce qui peut provoquer un syndrome greffon contre hôte. Par erreur de conception, et un peu par esprit de systéme, les efforts par le passé étaient dirigés sur la modification et la destruction des systémes lymphoréticulaires grâce au traitement préalable du donneur ou des organes transplantés, par médicaments, radiation ou autres moyens. Actuellement, I’idée directrice est de garder intacte les systémes lymphoréticulaires qui deviennent alors le site d’une circulation à double sens aprés transplantation. Avec la puissante immunodépression que fournit le FK 506, les cellules lymphoréticulaires du donneur peuvent circuler chez le receveur sans créer de syndrome du greffon contre hôte clinique et les cellules de la greffe s’assimilent à celles du receveur (chimérisme local) sans provoquer de rejet. Même si I’on évite le rejet ou le syndrome greffon contre hôte, il existe, à côté de ces entités, des relations métaboliques entre les organes greffés ainsi qu’entre les organes greffés et les viscéres du receveur laissés en place, qui peuvent influencer I’avenir soit des organes greffés, soit des organes laissés en place. Parmi les échanges métaboliques les mieux connus actuellement, il y a les facteurs splanchniques hépatotrophes endogénes, dont I’insuline est la mieux

  9. Radiative muon capture in nuclei

    SciTech Connect

    Doebeli, M.; Doser, M.; van Elmbt, L.; Schaad, M.W.; Truoel, P.; Bay, A.; Perroud, J.P.; Imazato, J.; Ishikawa, T.

    1988-04-01

    The energy spectra of photons following negative muon absorption in /sup 12/C, /sup 16/O, /sup 27/Al, /sup 40/Ca, /sup nat/Fe, /sup 165/Ho, and /sup 209/Bi have been measured with two NaI spectrometers. The branching ratios for the emission of high energy photons give information on the induced pseudoscalar coupling constant g/sub P/ in nuclear matter. The data for light nuclei are in agreement with the theoretical calculations using the nucleonic value of g/sub P/approx. =7g/sub A/ predicted by the partially conserved axial vector current hypothesis, while significantly lower values of g/sub P/ are required to fit the data of the heavier elements with presently existing theoretical predictions. Disregarding the remaining theoretical uncertainties, these results can be interpreted as a further indication of the renormalization of the nucleonic form factors inside the nucleus.

  10. Atmospheric muons and neutrinos, and the neutrino-induced muon flux underground

    NASA Technical Reports Server (NTRS)

    Liland, A.

    1985-01-01

    The diffusion equation for neutrino-induced cosmic ray muons underground was solved. The neutrino-induced muon flux and charge ratio underground have been calculated. The calculated horizontal neutrino-induced muon flux in the energy range 0.1 - 10000 GeV is in agreement with the measured horizontal flux. The calculated vertical flux above 2 GeV is in agreement with the measured vertical flux. The average charge ratio of neutrino-induced muons underground was found to be mu+/mu- = 0.40.

  11. Developpement des betons semi autoplacants a rheologie adaptee pour des infrastructures

    NASA Astrophysics Data System (ADS)

    Sotomayor Cruz, Cristian Daniel

    BSAP-I optimisés à travers une caractérisation complète des propriétés mécaniques et de la durabilité a été réalisée. A la suite de cette étude, les résultats obtenus nous permettent de conclure que : (1) L'utilisation d'un BSAP-I avec un gros granulat de 5 - 14 mm, des rapports E/L = 0,37 et S/G = 0,52 et une teneur en air de 6 à 9% a été possible en conférant un équilibre optimal fluidité / stabilité à l'état frais, ainsi qu'un niveau de thixotropie adéquate au chantier permettant d'optimiser la conception du coffrage des piliers de pont et de conférer des qualités de surfaces très acceptables de ces infrastructures. (2) La méthode adaptée pour l'essai L-Box contenant 2 barres et une vibration de 5 secondes a permis de bien caractériser la capacité de remplissage d'un BSAP-I. (3) L'utilisation d'un plan factoriel 23 a permis d'obtenir des modèles statistiques fiables, capables de prédire les propriétés rhéologiques à l'état frais et les résistances en compression des BSAP-I avec des dosages en liant entre 370 et 420 kg/m3, des rapports E/L entre 0,34 et 0,40 et S/G entre 0,47 et 0,53. (4) Des mesures de vitesse d'écoulement T40 d'un BSAP-I sont très semblables à celles d'un BAP. En plus, des valeurs T40 montrent une bonne corrélation linéaire avec celles de T400 mesurés dans la boîte L-Box. (5) À la frontière du BAP et du BCV, une bande rhéologique possédant un τ0 entre 30 et 320 Pa et un η entre 10 et 140 Pa.s a été trouvée pour la conception optimale des BSAP-I. (6) Les BSAP-I optimisés ont également conféré une très bonne performance à l'état frais, en permettant maintenir un bon équilibre entre la rhéologie et la stabilité dans le temps, lorsqu'on utilise une énergie de vibration minimale pour amorcer son écoulement. (7) À l'état durci Les BSAP-I ont conféré une bonne performance présentant des résistances mécaniques élevées et des niveaux négligeables de pénétration aux ions chlores

  12. Une étude rétrospective sur le cancer de l'ovaire avec un recul médian de 42 mois

    PubMed Central

    Raherinantenaina, Fanomezantsoa; Rakotomena, Solonirina Davidà; Hasiniatsy, Nomeharisoa Rodrigue Emile; Rakototiana, Felantsoa Auberlin; Rafaramino, Florine; Ratsimba, Hery Nirina Rakoto

    2015-01-01

    Le cancer de l'ovaire est relativement fréquent mais grave et de mauvais pronostic. Le but de cette étude était de mettre en évidence les aspects épidémiologique, diagnostique, thérapeutique et évolutif de cette pathologie maligne prise en charge dans un pays en développement. Il s'agit d'une étude rétrospective et descriptive de 10 ans (2000- 2009) effectuée dans un CHU de chirurgie générale et d'Oncologie sur 62 patientes ayant développé un cancer de l'ovaire et opérées à visée curative. L’âge moyen des patientes était de 43 ans dont 53,23% avaient plus de 45 ans. Le dosage sanguin du CA-125 était positif chez 10 patientes sur 12. Les tumeurs étaient découvertes à l’échographie dans 87,10% des cas et à la laparotomie dans 12,90%. L'hystérectomie totale avec annexectomie bilatérale était l'intervention la plus pratiquée (64,52%). Les suites opératoires précoces étaient simples. Dix patientes étaient opérées de second regard (16,13%) pour des récidives locorégionales. Les tumeurs épithéliales étaient le type histologique le plus fréquent (93,55%) dont 79% au stade avancé (Ic-IV) et 21% au stade précoce (Ia-Ib). La chimiothérapie adjuvante était administrée chez 22,60% des patientes. Avec un recul médian de 42 mois, 29 patientes étaient perdues de vue. L’évolution était favorable dans 27,42% et dans 25,81% les décès se sont survenus en postopératoire tardif. Le cancer de l'ovaire n’était pas fréquent mais grave compte tenu des stades avancés et du taux élevé des décès postopératoires tardifs qui étaient largement observés chez les patientes privées d'une chimiothérapie adéquate. PMID:26113942

  13. Muon calculations for the polarized proton beamline

    SciTech Connect

    Cossairt, J.D.

    1986-11-01

    Monte Carlo calculations of the muon intensities due to the new polarized proton beam using the program CASIM are reported. Results are reported in terms of tissue absorbed dose per incident proton. (LEW)

  14. Intense muon beams and neutrino factories

    SciTech Connect

    Parsa, Z.

    2000-10-05

    High intensity muon sources are needed in exploring neutrino factories, lepton flavor violating muon processes, and lower energy experiments as the stepping phase towards building higher energy {mu}{sup +}{mu}{sup {minus}} colliders. We present a brief overview, sketch of a neutrino source, and an example of a muon storage ring at BNL with detector(s) at Fermilab, Sudan, etc. Physics with low energy neutrino beams based on muon storage rings ({mu}SR) and conventional Horn Facilities are described and compared. CP violation Asymmetries and a new Statistical Figure of Merit to be used for comparison is given. Improvements in the sensitivity of low energy experiments to study Flavor changing neutral currents are also included.

  15. Mapping Overburden and Cave Networks with Muons

    NASA Astrophysics Data System (ADS)

    Prettyman, T. H.; Titus, T. N.; Boston, P. J.; Koontz, S. L.; Miller, R. S.

    2015-10-01

    We describe the use of highly-penetrating muons produced by cosmic ray showers to measure overburden and image the rock formation around terrestrial/extraterrestrial caves, and implications for cave science, exploration, and habitation.

  16. MUON ACCELERATION WITH THE RACETRACK FFAG

    SciTech Connect

    TRBOJEVIC,D.; EBERHARD, K.; SESSLER, A.

    2007-06-25

    Muon acceleration for muon collider or neutrino factory is still in a stage where further improvements are likely as a result of further study. This report presents a design of the racetrack non-scaling Fixed Field Alternating Gradient (NS-FFAG) accelerator to allow fast muon acceleration in small number of turns. The racetrack design is made of four arcs: two arcs at opposite sides have a smaller radius and are made of closely packed combined function magnets, while two additional arcs, with a very large radii, are used for muon extraction, injection, and RF accelerating cavities. The ends of the large radii arcs are geometrically matched at the connections to the arcs with smaller radii. The dispersion and both horizontal and vertical amplitude fictions are matched at the central energy.

  17. Topcolor and the First Muon Collider

    SciTech Connect

    Hill, C.T.

    1998-04-01

    We describe a class of models of electroweak symmetry breaking that involve strong dynamics and top quark condensation. A new scheme based upon a seesaw mechanism appears particularly promising. Various implications for the first-stage muon collider are discussed.

  18. Etude des phenomenes dynamiques ultrarapides et des caracteristiques impulsionnelles d'emission terahertz du supraconducteur YBCO

    NASA Astrophysics Data System (ADS)

    Savard, Stephane

    Les premieres etudes d'antennes a base de supraconducteurs a haute temperature critique emettant une impulsion electromagnetique dont le contenu en frequence se situe dans le domaine terahertz remontent a 1996. Une antenne supraconductrice est formee d'un micro-pont d'une couche mince supraconductrice sur lequel un courant continu est applique. Un faisceau laser dans le visible est focalise sur le micro-pont et place le supraconducteur dans un etat hors-equilibre ou des paires sont brisees. Grace a la relaxation des quasiparticules en surplus et eventuellement de la reformation des paires supraconductrices, nous pouvons etudier la nature de la supraconductivite. L'analyse de la cinetique temporelle du champ electromagnetique emis par une telle antenne terahertz supraconductrice s'est averee utile pour decrire qualitativement les caracteristiques de celle-ci en fonction des parametres d'operation tels que le courant applique, la temperature et la puissance d'excitation. La comprehension de l'etat hors-equilibre est la cle pour comprendre le fonctionnement des antennes terahertz supraconductrices a haute temperature critique. Dans le but de comprendre ultimement cet etat hors-equilibre, nous avions besoin d'une methode et d'un modele pour extraire de facon plus systematique les proprietes intrinseques du materiau qui compose l'antenne terahertz a partir des caracteristiques d'emission de celle-ci. Nous avons developpe une procedure pour calibrer le spectrometre dans le domaine temporel en utilisant des antennes terahertz de GaAs bombarde aux protons H+ comme emetteur et detecteur. Une fois le montage calibre, nous y avons insere une antenne emettrice dipolaire de YBa 2Cu3O7-delta . Un modele avec des fonctions exponentielles de montee et de descente du signal est utilise pour lisser le spectre du champ electromagnetique de l'antenne de YBa 2Cu3O7-delta, ce qui nous permet d'extraire les proprietes intrinseques de ce dernier. Pour confirmer la validite du modele

  19. Development of a Portable Muon Witness System

    SciTech Connect

    Aguayo Navarrete, Estanislao; Kouzes, Richard T.; Orrell, John L.

    2011-01-01

    Since understanding and quantifying cosmic ray induced radioactive backgrounds in copper and germanium are important to the MAJORANA DEMONSTRATOR, methods are needed for monitoring the levels of such backgrounds produced in materials being transported and processed for the experiment. This report focuses on work conducted at Pacific Northwest National Laboratory to develop a muon witness system as a one way of monitoring induced activities. The operational goal of this apparatus is to characterize cosmic ray exposure of materials. The cosmic ray flux at the Earth’s surface is composed of several types of particles, including neutrons, muons, gamma rays and protons. These particles induce nuclear reactions, generating isotopes that contribute to the radiological background. Underground, the main mechanism of activation is by muon produced spallation neutrons since the hadron component of cosmic rays is removed at depths greater than a few tens of meters. This is a sub-dominant contributor above ground, but muons become predominant in underground experiments. For low-background experiments cosmogenic production of certain isotopes, such as 68Ge and 60Co, must be accounted for in the background budgets. Muons act as minimum ionizing particles, depositing a fixed amount of energy per unit length in a material, and have a very high penetrating power. Using muon flux measurements as a “witness” for the hadron flux, the cosmogenic induced activity can be quantified by correlating the measured muon flux and known hadronic production rates. A publicly available coincident muon cosmic ray detector design, the Berkeley Lab Cosmic Ray Detector (BLCRD), assembled by Juniata College, is evaluated in this work. The performance of the prototype is characterized by assessing its muon flux measurements. This evaluation is done by comparing data taken in identical scenarios with other cosmic ray telescopes. The prototype is made of two plastic scintillator paddles with

  20. Muon dynamics in a toroidal sector magnet

    SciTech Connect

    Gallardo, J.C.; Fernow, R.; Palmer, R.B.

    1997-09-17

    The present scenario for the cooling channel in a high brightness muon collider calls for a quasi-continuous solenoidal focusing channel. The beam line consists of a periodic array of rf cavities and approximately 2 cm long LiH absorbers immersed in a solenoid with alternating focusing field (FOFO). The authors present a Hamiltonian formulation of muon dynamics in toroidal sector solenoids (bent solenoid).

  1. Preparations for Muon Experiments at Fermilab

    SciTech Connect

    Syphers, M.J.; Popovic, M.; Prebys, E.; Ankenbrandt, C.; /Muons Inc., Batavia

    2009-05-01

    The use of existing Fermilab facilities to provide beams for two muon experiments--the Muon to Electron Conversion Experiment (Mu2e) and the New g-2 Experiment--is under consideration. Plans are being pursued to perform these experiments following the completion of the Tevatron Collider Run II, utilizing the beam lines and storage rings used today for antiproton accumulation without considerable reconfiguration.

  2. Muon Emittance Exchange with a Potato Slicer

    SciTech Connect

    Summers, D. J.; Hart, T. L.; Acosta, J. G.; Cremaldi, L. M.; Oliveros, S. J.; Perera, L. P.; Neuffer, D. V.

    2015-04-15

    We propose a novel scheme for final muon ionization cooling with quadrupole doublets followed by emittance exchange in vacuum to achieve the small beam sizes needed by a muon collider. A flat muon beam with a series of quadrupole doublet half cells appears to provide the strong focusing required for final cooling. Each quadrupole doublet has a low beta region occupied by a dense, low Z absorber. After final cooling, normalized transverse, longitudinal, and angular momentum emittances of 0.100, 2.5, and 0.200 mm-rad are exchanged into 0.025, 70, and 0.0 mm-rad. A skew quadrupole triplet transforms a round muon bunch with modest angular momentum into a flat bunch with no angular momentum. Thin electrostatic septa efficiently slice the flat bunch into 17 parts. The 17 bunches are interleaved into a 3.7 meter long train with RF deflector cavities. Snap bunch coalescence combines the muon bunch train longitudinally in a 21 GeV ring in 55 µs, one quarter of a synchrotron oscillation period. A linear long wavelength RF bucket gives each bunch a different energy causing the bunches to drift in the ring until they merge into one bunch and can be captured in a short wavelength RF bucket with a 13% muon decay loss and a packing fraction as high as 87 %.

  3. High intensity muon beam source for neutrino beam experiments

    NASA Astrophysics Data System (ADS)

    Kamal Sayed, Hisham

    2015-09-01

    High intensity muon beams are essential for Muon accelerators like Neutrino Factories and Muon Colliders. In this study we report on a global optimization of the muon beam production and capture based on end-to-end simulations of the Muon Front End. The study includes the pion beam production target geometry, capture field profile, and forming muon beam into microbunches for further acceleration. The interplay between the transverse and longitudinal beam dynamics during the capture and transport of muon beam is evaluated and discussed. The goal of the optimization is to provide a set of design parameters that delivers high intensity muon beam that could be fit within the acceptance of a muon beam accelerator.

  4. Lignes directrices canadiennes sur l’utilisation sécuritaire et efficace des opioïdes pour la douleur chronique non cancéreuse

    PubMed Central

    Kahan, Meldon; Wilson, Lynn; Mailis-Gagnon, Angela; Srivastava, Anita

    2011-01-01

    Résumé Objectif Présenter aux médecins de famille un résumé clinique pratique sur la prescription d’opioïdes à des populations particulières en se fondant sur les recommandations faites dans les lignes directrices canadiennes sur l’utilisation sécuritaire et efficace des opioïdes pour la douleur chronique non cancéreuse. Qualité des données Pour produire les lignes directrices, les chercheurs ont effectué une synthèse critique de la littérature médicale en insistant plus précisément sur les études de l’efficacité et de la sécurité des opioïdes dans des populations particulières. Message principal Les médecins de famille peuvent atténuer les risques de surdose, de sédation, d’usage abusif et de dépendance grâce à des stratégies adaptées à l’âge et à l’état de santé des patients. Dans le cas de patients à risque de dépendance, on devrait réserver les opioïdes aux douleurs nociceptives ou neuropathiques bien définies qui n’ont pas répondu aux traitements de première intention. Il faut procéder lentement au titrage des opioïdes, avec des dispensations fréquentes et une étroite surveillance pour dépister tout signe d’usage abusif. Une dépendance aux opioïdes suspectée est prise en charge au moyen d’une thérapie structurée aux opioïdes, d’un traitement à la méthadone ou à la buprénorphine ou encore d’un traitement fondé sur l’abstinence. Les patients souffrant de troubles de l’humeur ou d’anxiété ont tendance à avoir une réponse analgésique atténuée aux opioïdes, sont à risque plus élevé d’usage abusif et prennent souvent des sédatifs qui interagissent défavorablement avec les opioïdes. Il faut prendre des précautions semblables à celles utilisées avec d’autres patients à risque élevé. Il faut faire un sevrage progressif si la douleur du patient demeure sévère même avec un essai adéquat de thérapie aux opioïdes. Chez les personnes âgées, la s

  5. Modular detector for deep underwater registration of muons and muon groups

    NASA Technical Reports Server (NTRS)

    Demianov, A. I.; Sarycheva, L. I.; Sinyov, N. B.; Varadanyan, I. N.; Yershov, A. A.

    1985-01-01

    Registration and identification of muons and muon groups penetrating into the ocean depth, can be performed using a modular multilayer detector with high resolution bidimensional readout - deep underwater calorimeter (project NADIR). Laboratory testing of a prototype sensor cell with liquid scintillator in light-tight casing, testifies to the practicability of the full-scale experiment within reasonable expences.

  6. Proceedings of the International Workshop on Low Energy Muon Science: LEMS`93

    SciTech Connect

    Leon, M.

    1994-01-01

    This report contains papers on research with low energy muons. Topics cover fundamental electroweak physics; muonic atoms and molecules, and muon catalyzed fusion; muon spin research; and muon facilities. These papers have been indexed and cataloged separately.

  7. R&D Toward a Neutrino Factory and Muon Collider

    SciTech Connect

    Zisman, Michael S

    2011-03-20

    Significant progress has been made in recent years in R&D towards a neutrino factory and muon collider. The U.S. Muon Accelerator Program (MAP) has been formed recently to expedite the R&D efforts. This paper will review the U.S. MAP R&D programs for a neutrino factory and muon collider. Muon ionization cooling research is the key element of the program. The first muon ionization cooling demonstration experiment, MICE (Muon Ionization Cooling Experiment), is under construction now at RAL (Rutherford Appleton Laboratory) in the UK. The current status of MICE will be described.

  8. Study of muon-induced neutron production using accelerator muon beam at CERN

    SciTech Connect

    Nakajima, Y.; Lin, C. J.; Ochoa-Ricoux, J. P.; Draeger, E.; White, C. G.; Luk, K. B.; Steiner, H.

    2015-08-17

    Cosmogenic muon-induced neutrons are one of the most problematic backgrounds for various underground experiments for rare event searches. In order to accurately understand such backgrounds, experimental data with high-statistics and well-controlled systematics is essential. We performed a test experiment to measure muon-induced neutron production yield and energy spectrum using a high-energy accelerator muon beam at CERN. We successfully observed neutrons from 160 GeV/c muon interaction on lead, and measured kinetic energy distributions for various production angles. Works towards evaluation of absolute neutron production yield is underway. This work also demonstrates that the setup is feasible for a future large-scale experiment for more comprehensive study of muon-induced neutron production.

  9. Caracterisation du coefficient de retrodiffusion radar des surfaces d'hydrocarbure: Modelisation et interpretation

    NASA Astrophysics Data System (ADS)

    Charbonneau, Francois

    La surveillance maritime est un domaine d'applications ou l'interet politique et scientifique croit constamment au Canada. Un des outils privilegies pour la surveillance maritime est l'acquisition de donnees radars, par des systemes aeroportes ou spatio-portes (ERS-2, RADARSAT et Envisat). Par leur grande couverture spatiale, ainsi que leur sensibilite a la geometrie de surface, les donnees radars permettent, en autres, la detection de cibles ponctuelles (bateaux), estimation des vents, detection des glaces de mer, ainsi que la detection de deversement d'hydrocarbure. Les limites et les avantages de la detection d'hydrocarbure par acquisitions de donnees radars sont bien connus, mais il reste encore des lacunes au niveau de l'extraction des parametres physiques d'une surface d'hydrocarbure. Ce projet a pour objectif de caracteriser le coefficient de retrodiffusion radar associe a une surface d'hydrocarbure en milieu oceanique, par l'introduction d'un modele thermodynamique d'attenuation de la surface, au modele theorique radar IEM. Le modele global permet de simuler le comportement de sigma° en fonction des proprietes visco-elastiques, ainsi que de l'epaisseur de la couche d'hydrocarbure et en fonction des parametres d'acquisition radar. Le modele developpe fut valide a partir des donnees SIR-C acquises lors d'experimentations controlees. A partir des informations environnementales et du type d'hydrocarbure, notre modele a permis d'estime le contraste d'intensite avec une precision de 1 a 1,5 dB, a la bande C. Alors qu'a la bande L, l'erreur sur le contraste est d'environ 1,5 a 2 dB sur l'ensemble des mesures. Ce qui est excellant considerant l'heterogeneite des surfaces analysees. Egalement, nous effectuons des analyses multi-polarisees et polarimetriques avec les donnees SIR-C acquises au-dessus de sites experimentaux. II en ressort que le ratio de polarisation VV/HH, ainsi que le facteur d'anisotropie sont des pistes de recherche prometteuses qu'il faudra

  10. Muon Acceleration - RLA and FFAG

    SciTech Connect

    Bogacz, Alex

    2011-10-01

    Various acceleration schemes for muons are presented. The overall goal of the acceleration systems: large acceptance acceleration to 25 GeV and 'beam shaping' can be accomplished by various fixed field accelerators at different stages. They involve three superconducting linacs: a single pass linear Pre-accelerator followed by a pair of multi-pass Recirculating Linear Accelerators (RLA) and finally a non-scaling FFAG ring. The present baseline acceleration scenario has been optimized to take maximum advantage of appropriate acceleration scheme at a given stage. The solenoid based Pre-accelerator offers very large acceptance and facilitates correction of energy gain across the bunch and significant longitudinal compression trough induced synchrotron motion. However, far off-crest acceleration reduces the effective acceleration gradient and adds complexity through the requirement of individual RF phase control for each cavity. The RLAs offer very efficient usage of high gradient superconducting RF and ability to adjust path-length after each linac pass through individual return arcs with uniformly periodic FODO optics suitable for chromatic compensation of emittance dilution with sextupoles. However, they require spreaders/recombiners switchyards at both linac ends and significant total length of the arcs. The non-scaling Fixed Field Alternating Gradient (FFAG) ring combines compactness with very large chromatic acceptance (twice the injection energy) and it allows for large number of passes through the RF (at least eight, possibly as high as 15).

  11. Formation et Evolution des Quasars et Contraintes cosmologiques

    NASA Astrophysics Data System (ADS)

    Hatziminaoglou, Evanthia

    2000-06-01

    Cette thèse porte sur l'étude de l'évolution des quasars. Elle en aborde certains aspects théoriques et observationnels, ainsi que la construction des grands échantillons de quasars dans le but à long terme de combiner le tout dans un test cosmologique géométrique pour déterminer les valeurs des paramètres cosmologiques Omega et Lambda. Les paramètres cosmologiques Omegaspan>et Lambdaspan>décrivent la géométrie globale de l'Univers. En faisant des hypothèses raisonnables sur la distribution spatiale et l'évolution des objets astrophysiques (galaxies, amas des galaxies, quasars), on peut déterminer les valeurs de ces paramètres qui sont cohérentes avec ces hypothèses. Les tests cosmologiques traditionnels ont besoin de ''chandelles standards'', objets dont les propriétés intrinsèques sont indépendantes des distances. De tels objets sont probablement fictifs. Néanmoins, certains de ces tests cosmologiques peuvent être adaptés si l'évolution individuelle, ou au moins l'évolution statistique d'une population d'objets est connue. La question de la nature de l'évolution des quasars a très vite été posée et des réponses ''phénoménologiques'' ont d'abord été données. Ces réponses ne faisaient que donner une forme mathématique à l'évolution mais n'expliquaient rien de la physique duphénomène. Les premières tentatives de construction d'un modèle physique, liées au processus d'accrétion sur un trou noir et à la théorie de la formation de l'Univers ont commencé à la fin des années 80. Depuis, des dizaines de modèles tentent d'expliquer les observations, qui sont les résultats de l'étude d'objets de plus en plus nombreux. Au cours de cette thèse, le test V/Vmax a été appliqué sur l'échantillon du Large Bright Quasar Survey en montrant 1) que l'échantillon était biaisé à cause des critères de sélection et 2) que la (simple) loi de Pure Evolution en Luminosité n'était pas une bonne approximation à tout

  12. X-ray Production By Cosmic Muons

    NASA Astrophysics Data System (ADS)

    Mrdja, D.; Bikit, I.; Aničin, I.; Vesković, M.; Forkapić, S.

    2007-04-01

    Muons have a small cross section for interactions and high energy, so they are very penetrating and give the significant contribution to the gamma spectra of Ge detectors, even in deep underground laboratories. One of the muon interaction effects with material is X-rays production. Having in mind that gold is often used as a detectors component, in this paper the production of X-rays in gold sample is analyzed by using an coincidence system based on plastic scintillation detector and Ge detector. The Au disc-shaped sample with mass of 40.6 g, radius 3.34 cm and 0.06 cm thickness was inside 12 cm thick lead shield of extended range HPGe detector. The plastic detector of 0.5 × 0.5 × 0.05 m dimensions was placed above the lead shield at the distance of 32 cm from detector endcap. The producing rate of Kα rays per Au mass unit from coincidence gamma spectrum is determined as R ~7.1 × 10-4 g-1s-1. Taking in account the measured muon flux of Φ=54 s-1m-2, the muon cross section σKα~ 43 Barn, for Au Kα X-rays production is calculated. Also, the cross sections of X-ray production by cosmic muons in lead and tungsten are measured. Unexpectedly, the results obtained did not reveal Z dependence in the Z= 74-82 region.

  13. Approche à l’égard des nouveaux anticoagulants oraux en pratique familiale

    PubMed Central

    Douketis, James; Bell, Alan David; Eikelboom, John; Liew, Aaron

    2014-01-01

    Résumé Objectif Comparer les caractéristiques principales des nouveaux anticoagulants oraux (NACO), soit le dabigatran, le rivaroxaban et l’apixaban, et répondre aux questions qui font surface lors de la comparaison de ces agents. Qualité des données Une recherche dans PubMed a été effectuée afin de relever les études cliniques récentes (de janvier 2008 à la semaine 32 de 2013) portant sur l’emploi des NACO pour la prévention des AVC dans les cas de fibrillation auriculaire (FA) et pour le traitement de la thromboembolie veineuse aiguë. Message principal Selon 3 essais d’envergure, tous les NACO sont au moins aussi efficaces que la warfarine dans la prévention des AVC chez les patients atteints d’une FA non valvulaire, et au moins aussi sûrs pour ce qui est du risque de saignement. Des méta-analyses de ces essais ont montré que, comparativement au traitement par la warfarine, les NACO avaient réduit la mortalité totale, la mortalité d’origine cardiovasculaire et les saignements intracrâniens, et était aussi ressortie une tendance vers la réduction des saignements généraux. Du côté pratique, les avantages des NACO par rapport à la warfarine sont : posologie orale fixe uniquotidienne ou biquotidienne sans devoir surveiller la coagulation et peu d’interactions connues ou définies avec d’autres médicaments ou des aliments. Les désavantages potentiels des NACO sont notamment un risque de saignement qui serait accru chez les patients de plus de 75 ans, une hausse des saignements gastro-intestinaux majeurs avec des doses élevées de dabigatran, une hausse des cas de dyspepsie avec le dabigatran, l’absence d’un test de laboratoire de routine visant à mesurer de façon fiable l’effet anticoagulant et l’absence d’antidote pour renverser l’effet anticoagulant. Aucun essai randomisé contrôlé n’a effectué de comparaison directe des NACO, et le choix d’un NACO est influencé par les caract

  14. Showering cosmogenic muons in a large liquid scintillator

    NASA Astrophysics Data System (ADS)

    Grassi, Marco; Evslin, Jarah; Ciuffoli, Emilio; Zhang, Xinmin

    2014-09-01

    We present the results of FLUKA simulations of the propagation of cosmogenic muons in a 20 kton spherical liquid scintillator detector underneath 700 to 900 meters of rock. A showering muon is one which deposits at least 3 GeV in the detector in addition to ionization energy. We find that 20 percent of muons are showering and a further 11 percent of muon events are muon bundles, of which more than one muon enters the detector. In this range the showering and bundle fractions are robust against changes in the depth and topography, thus the total shower and bundle rate for a given experiment can be obtained by combining our results with an estimate for the total muon flux. One consequence is that a straightforward adaptation of the full detector showering muon cuts used by KamLAND to JUNO or RENO 50 would yield a nearly vanishing detector efficiency.

  15. Pion production for neutrino factories and muon colliders

    SciTech Connect

    Mokhov, N.V.; Guidman, K.K.; Strait, J.B.; Striganov, S.I.; /Fermilab

    2009-12-01

    Optimization of pion and muon production/collection for neutrino factories and muon colliders is described along with recent developments of the MARS15 code event generators and effects influencing the choice of the optimal beam energy.

  16. Strongest Pulsed Muon Source at J-PARC MUSE

    SciTech Connect

    Miyake, Y.; Shimomura, K.; Kawamura, N.; Strasser, P.; Koda, A.; Fujimori, H.; Makimura, S.; Nakahara, K.; Kato, M.; Takeshita, S.; Nishiyama, K.; Kobayashi, Y.; Kojima, K.; Kadono, R.; Higemoto, W.; Ito, T.; Ninomiya, K.; Hiraishi, M.; Miyazaki, M.; Kubo, K.

    2011-10-06

    The muon science facility (MUSE, abbreviation of MUon Science Establishment), along with the neutron, hadron, and neutrino facilities, is located in the Materials and Life Science Facility (MLF), which is a building integrated to include both neutron and muon science programs. On the November, 2009 beam cycle, we achieved extraction of the world's strongest pulsed muon beam at J-PARC MUSE by beam tuning at the Decay-Surface muon beam line (D-line). Surface muons ({mu}{sup +}) as much as 1.8x10{sup 6}/s were extracted with the use of 120 kW of protons from the Rapid Cycle Synchrotron (RCS), which corresponds to 1.5x10{sup 7}/s surface muons when a future proton beam reached at the intensity of 1MW. These intensities, at the future 1 MW operation, will correspond to more than ten times those at the RIKEN-RAL Muon facility.

  17. Listériose humaine : Expériences cliniques avec cette zoonose chez 12 patients en Estrie, Québec sur une période de 19 ans (1976 à 1995)

    PubMed Central

    Maziade, Pierre-Jean; Marcoux, J André

    1997-01-01

    Une étude rétrospective a été faite dans le but de réviser l’épidémiologie, les facteurs de risque, les manifestations cliniques et l’évolution des cas d’infection à Listeria monocytogenes en Estrie, Québec de 1976–1995. Les patients ont été repérés à partir des cultures positives et du diagnostic donné par le Service des maladies infectieuses du Centre hospitalier universitaire de Sherbrooke, Sherbrooke, Québec. Un total de 12 patients ont fait partie de l’étude. La septicémie non reliée à la grossesse (4/12) et la méningite (6/12) ont été les deux présentations cliniques majeures. Il y avait 1 cas de listériose de grossesse et 1 cas de granulomatosis infanti septica. Dix patients avaient au moins une condition prédisposante. Un seul décès a été attribué à l’infection à L monocytogenes. Des séquelles neurologiques ont été observées chez la moitié des patients avec méningite tandis qu’aucune séquelle a été notée chez ceux avec septicémie. En conclusion, la listériose est une maladie de patients âgés et immunocompromis. La présentation clinique et l’évolution ne sont pas différentes de ce qui a déjà été rapporté dans d’autres régions industrialisées. PMID:22514474

  18. Statistique des photons d'un laser à 4 niveaux soumis à un pompage optique

    NASA Astrophysics Data System (ADS)

    Chusseau, L.; Arnaud, J.; Philippe, F.

    2002-06-01

    Les lasers conventionnels à 4 niveaux peuvent délivrer de la lumière de statistique sous-Poissonienne même lorsqu'ils sont soumis à un pompage optique. Nous retrouvons exactement ces prédictions de l'optique quantique en supposant simplement que les atomes ont des niveaux d'énergie quantifiés interagissant avec un champ électromagnétique classique, la source du bruit optique étant les sauts quantiques entre niveaux. Des formules analytiques sont obtenues pour les deux paramètres clefs de la statistique des photons du laser: le facteur de Fano et la densité spectrale des photons émis.

  19. “Acceptation” et tolérance des allogreffes : nouveau concept

    PubMed Central

    STARZL, Thomas E.

    2010-01-01

    RÉSUMÉ La découverte du microchimérisme dans la transplantation de rein et de foie a permis de mieux comprendre « l’acceptation » des allogreffes, l’analyse des problèmes de conditionnement et la recherche de nouvelles orientations dans le traitement des greffes. En fonction de ce nouveau concept, seront ici discutées les relations avec les maladies infectieuses provoquées par des micro-organismes non cytopathologiques, les réponses aux questions autrefois posées, la réaction immunologique et les implications dans le domaine de l’immunologie générale. PMID:9622934

  20. Studies of muon-induced radioactivity at NuMI

    SciTech Connect

    Boehnlein, David j.; Leveling, A.F.; Mokhov, N.V.; Vaziri, K.; Iwamoto, Y.; Kasugai, Y.; Matsuda, N.; Nakashima, H.; Sakamoto, Y.; Hagiwara, M.; Iwase, Hiroshi; /KEK, Tsukuba /Kyoto U., KURRI /Pohang Accelerator Lab. /Shimizu, Tokyo /Tohoku U.

    2009-12-01

    The JASMIN Collaboration has studied the production of radionuclides by muons in the muon alcoves of the NuMI beamline at Fermilab. Samples of aluminum and copper are exposed to the muon field and counted on HpGe detectors when removed to determine their content of radioactive isotopes. We compare the results to MARS simulations and discuss the radiological implications for neutrino factories and muon colliders.

  1. THE POTENTIAL FOR NEUTRINO PHYSICS AT MUON COLLIDERS AND DEDICATED HIGH CURRENT MUON STORAGE RINGS

    SciTech Connect

    BIGI,I.; BOLTON,T.; FORMAGGIO,J.; HARRIS,D.; MORFIN,J.; SPENTZOURIS,P.; YU,J.; KAYSER,B.; KING,B.J.; MCFARLAND,K.; PETROV,A.; SCHELLMAN,H.; VELASCO,M.; SHROCK,R.

    2000-05-11

    Conceptual design studies are underway for both muon colliders and high-current non-colliding muon storage rings that have the potential to become the first true neutrino factories. Muon decays in long straight sections of the storage rings would produce uniquely intense and precisely characterized two-component neutrino beams--muon neutrinos plus electron antineutrinos from negative muon decays and electron neutrinos plus muon antineutrinos from positive muons. This article presents a long-term overview of the prospects for these facilities to greatly extend the capabilities for accelerator-based neutrino physics studies for both high rate and long baseline neutrino experiments. As the first major physics topic, recent experimental results involving neutrino oscillations have motivated a vigorous design effort towards dedicated neutrino factories that would store muon beams of energies 50 GeV or below. These facilities hold the promise of neutrino oscillation experiments with baselines up to intercontinental distances and utilizing well understood beams that contain, for the first time, a substantial component of multi-GeV electron-flavored neutrinos. In deference to the active and fast-moving nature of neutrino oscillation studies, the discussion of long baseline physics at neutrino factories has been limited to a concise general overview of the relevant theory, detector technologies, beam properties, experimental goals and potential physics capabilities. The remainder of the article is devoted to the complementary high rate neutrino experiments that would study neutrino-nucleon and neutrino-electron scattering and would be performed at high performance detectors placed as close as is practical to the neutrino production straight section of muon storage rings in order to exploit beams with transverse dimensions as small as a few tens of centimeters.

  2. Muon Tracking to Detect Special Nuclear Materials

    SciTech Connect

    Schwellenbach, D.; Dreesen, W.; Green, J. A.; Tibbitts, A.; Schotik, G.; Borozdin, K.; Bacon, J.; Midera, H.; Milner, C.; Morris, C.; Perry, J.; Barrett, S.; Perry, K.; Scott, A.; Wright, C.; Aberle, D.

    2013-03-18

    Previous experiments have proven that nuclear assemblies can be imaged and identified inside of shipping containers using vertical trajectory cosmic-ray muons with two-sided imaging. These experiments have further demonstrated that nuclear assemblies can be identified by detecting fission products in coincidence with tracked muons. By developing these technologies, advanced sensors can be designed for a variety of warhead monitoring and detection applications. The focus of this project is to develop tomographic-mode imaging using near-horizontal trajectory muons in conjunction with secondary particle detectors. This will allow imaging in-situ without the need to relocate the objects and will enable differentiation of special nuclear material (SNM) from other high-Z materials.

  3. Muon (g-2) Technical Design Report

    SciTech Connect

    Grange, J.

    2015-01-27

    The Muon (g-2) Experiment, E989 at Fermilab, will measure the muon anomalous magnetic moment a factor-of-four more precisely than was done in E821 at the Brookhaven National Laboratory AGS. The E821 result appears to be greater than the Standard-Model prediction by more than three standard deviations. When combined with expected improvement in the Standard-Model hadronic contributions, E989 should be able to determine definitively whether or not the E821 result is evidence for physics beyond the Standard Model. After a review of the physics motivation and the basic technique, which will use the muon storage ring built at BNL and now relocated to Fermilab, the design of the new experiment is presented. This document was created in partial fulfillment of the requirements necessary to obtain DOE CD-2/3 approval.

  4. Muon Fluence Measurements for Homeland Security Applications

    SciTech Connect

    Ankney, Austin S.; Berguson, Timothy J.; Borgardt, James D.; Kouzes, Richard T.

    2010-08-10

    This report focuses on work conducted at Pacific Northwest National Laboratory to better characterize aspects of backgrounds in RPMs deployed for homeland security purposes. Two polyvinyl toluene scintillators were utilized with supporting NIM electronics to measure the muon coincidence rate. Muon spallation is one mechanism by which background neutrons are produced. The measurements performed concentrated on a broad investigation of the dependence of the muon flux on a) variations in solid angle subtended by the detector; b) the detector inclination with the horizontal; c) depth underground; and d) diurnal effects. These tests were conducted inside at Building 318/133, outdoors at Building 331G, and underground at Building 3425 at Pacific Northwest National Laboratory.

  5. Analyse de L'ancrage des Vortex Intergrains pour le Yttrium BARYUM(2) CUIVRE(3) OXYGENE(7) Polycristallin

    NASA Astrophysics Data System (ADS)

    Fournier, Patrick

    Le Modele de l'Etat Critique Generalise (MECG) est utilise pour decrire les proprietes magnetiques et de transport du YBa_2Cu_3O _7 polycristallin. Ce modele empirique permet de relier la densite de courant critique a la densite de lignes de flux penetrant dans la region intergrain. Deux techniques de mesures sont utilisees pour caracteriser nos materiaux. La premiere consiste a mesurer le champ au centre d'un cylindre creux en fonction du champ magnetique applique pour des temperatures comprises entre 20 et 85K. En variant l'epaisseur de la paroi du cylindre creux, il est possible de suivre l'evolution des cycles d'hysteresis et de determiner des champs caracteristiques qui varient en fonction de cette dimension. En utilisant un lissage des resultats experimentaux, nous determinons J _{co}, H_ {o} et n, les parametres du MECG. La forme des cylindres, avec une longueur comparable au diametre externe, entrai ne la presence d'un champ demagnetisant qui peut etre inclus dans le modele theorique. Ceci nous permet d'evaluer la fraction du volume ecrante, f _{g}, ainsi que le facteur demagnetisant N. Nous trouvons que J_{ co}, H_{o} et f_{g} dependent de la temperature, tandis que n et N (pour une epaisseur de paroi fixe) n'en dependent pas. La deuxieme technique consiste a mesurer le courant critique de lames minces en fonction du champ applique pour differentes temperatures. Nous utilisons un montage que nous avons developpe permettant d'effectuer ces mesures en contact direct avec le liquide refrigerant, i.e. dans l'azote liquide. Nous varions la temperature du liquide en variant la pression du gaz au-dessus du bain d'azote. Cette methode nous permet de balayer des temperatures entre 65K et la temperature critique du materiau ({~ }92K). Nous effectuons le lissage des courbes de courant critique en fonction du champ applique encore a l'aide du MECG, pour a nouveau obtenir ses parametres. Pour trois echantillons avec des traitements thermiques differents, les parametres

  6. PROTON BEAM REQUIREMENTS FOR A NEUTRINO FACTORY AND MUON COLLIDER

    SciTech Connect

    Zisman, Michael S.

    2009-12-11

    Both a Neutrino Factory and a Muon Collider place stringent demands on the proton beam used to generate the desired beam of muons. Here we discuss the advantages and challenges of muon accelerators and the rationale behind the requirements on proton beam energy, intensity, bunch length, and repetition rate. Example proton driver configurations that have been considered in recent years are also briefly indicated.

  7. Higgs boson and Z physics at the first muon collider

    SciTech Connect

    Demarteau, M.; Han, T.

    1998-01-01

    The potential for the Higgs boson and Z-pole physics at the first muon collider is summarized, based on the discussions at the ``Workshop on the Physics at the First Muon Collider and at the Front End of a Muon Collider``.

  8. Noninvasive Reactor Imaging Using Cosmic-Ray Muons

    NASA Astrophysics Data System (ADS)

    Miyadera, H.; Fujita, K.; Karino, Y.; Kume, N.; Nakayama, K.; Sano, Y.; Sugita, T.; Yoshioka, K.; Morris, C. L.; Bacon, J. D.; Borozdin, K. N.; Perry, J. O.; Mizokami, S.; Otsuka, Y.; Yamada, D.

    2015-10-01

    Cosmic-ray-muon imaging is proposed to assess the damages to the Fukushima Daiichi reactors. Simulation studies showed capability of muon imaging to reveal the core conditions.The muon-imaging technique was demonstrated at Toshiba Nuclear Critical Assembly, where the uranium-dioxide fuel assembly was imaged with 3-cm spatial resolution after 1 month of measurement.

  9. Jet production in muon-proton and muon-nuclei scattering at Fermilab-E665

    SciTech Connect

    Salgado, C.W.; E665 Collaboration

    1993-08-01

    Measurements of multi-jet production rates from Muon-Proton Muon- Nuclei scattering at Fermilab-E665 are presented. Jet rates are defined by the JADE clustering algorithm. Rates in Muon-Proton deep-inelastic scattering are compared to perturbative Quantum Chromodynamics (PQCD) and Monte Carlo model predictions. We observe hadronic (2+1)-jet rates which are a factor of two higher than PQCD predictions at the partonic level. Preliminary results from jet production on heavy targets, in the shadowing region, show a suppression of the jet rates as compared to deuterium. The two- forward jet sample present higher suppression as compared to the one-forward jet sample.

  10. Characterisation of the muon beams for the Muon Ionisation Cooling Experiment

    SciTech Connect

    Adams, D.; et al.,

    2013-10-01

    A novel single-particle technique to measure emittance has been developed and used to characterise seventeen different muon beams for the Muon Ionisation Cooling Experiment (MICE). The muon beams, whose mean momenta vary from 171 to 281 MeV/c, have emittances of approximately 1.5--2.3 \\pi mm-rad horizontally and 0.6--1.0 \\pi mm-rad vertically, a horizontal dispersion of 90--190 mm and momentum spreads of about 25 MeV/c. There is reasonable agreement between the measured parameters of the beams and the results of simulations. The beams are found to meet the requirements of MICE.

  11. Regles de fusion en theorie des champs conformes

    NASA Astrophysics Data System (ADS)

    Begin, Luc

    1999-10-01

    Les théories de champs conformes constituent un domaine de recherche très actif avec de nombreuses applications en physique statistique, en matière condensée, en théorie des cordes, en mathématiques, etc. Nous analysons ici le calcul des règles de fusion dans les modèles Wess- Zumino-Witten par des méthodes positives. Les règles de fusion sont des quantités importantes puisqu'elles indiquent comment se combinent les champs primaires de la théorie. L'approche présentée est basée sur l'hypothèse que les règles de fusion sont décrites par un système d'inéquations linéaire et homogène et mène au concept original de «base de fusion». Cette approche simple et générale permet d'utiliser les méthodes combinatoires et de programmation linéaire pour construire les fonctions génératrices et les bases de fusion. Cette méthode permet d'obtenir des résultats originaux et explicites pour les algèbres su (3), su (4) et sp (4).

  12. Constraints on muon-specific dark forces

    NASA Astrophysics Data System (ADS)

    Karshenboim, Savely G.; McKeen, David; Pospelov, Maxim

    2014-10-01

    The recent measurement of the Lamb shift in muonic hydrogen allows for the most precise extraction of the charge radius of the proton which is currently in conflict with other determinations based on e-p scattering and hydrogen spectroscopy. This discrepancy could be the result of some new muon-specific force with O(1-100) MeV force carrier—in this paper we concentrate on vector mediators. Such an explanation faces challenges from the constraints imposed by the g-2 of the muon and electron as well as precision spectroscopy of muonic atoms. In this work we complement the family of constraints by calculating the contribution of hypothetical forces to the muonium hyperfine structure. We also compute the two-loop contribution to the electron parity-violating amplitude due to a muon loop, which is sensitive to the muon axial-vector coupling. Overall, we find that the combination of low-energy constraints favors the mass of the mediator to be below 10 MeV and that a certain degree of tuning is required between vector and axial-vector couplings of new vector particles to muons in order to satisfy constraints from muon g-2. However, we also observe that in the absence of a consistent standard model embedding high-energy weak-charged processes accompanied by the emission of new vector particles are strongly enhanced by (E/mV)2, with E a characteristic energy scale and mV the mass of the mediator. In particular, leptonic W decays impose the strongest constraints on such models completely disfavoring the remainder of the parameter space.

  13. Large muon electric dipole moment from flavor?

    SciTech Connect

    Hiller, Gudrun; Huitu, Katri; Rueppell, Timo; Laamanen, Jari

    2010-11-01

    We study the prospects and opportunities of a large muon electric dipole moment (EDM) of the order (10{sup -24}-10{sup -22}) ecm. We investigate how natural such a value is within the general minimal supersymmetric extension of the standard model with CP violation from lepton flavor violation in view of the experimental constraints. In models with hybrid gauge-gravity-mediated supersymmetry breaking, a large muon EDM is indicative for the structure of flavor breaking at the Planck scale, and points towards a high messenger scale.

  14. Muon production in extended air shower simulations.

    PubMed

    Pierog, T; Werner, K

    2008-10-24

    Whereas air shower simulations are very valuable tools for interpreting cosmic ray data, there is a long-standing problem: it is difficult to accommodate at the same time the longitudinal development of air showers and the number of muons measured on the ground. Using a new hadronic interaction model (EPOS) in air shower simulations produces much more muons, in agreement with results from the HiRes-MIA experiment. We find that this is mainly due to a better description of (anti) baryon production in hadronic interactions. This is an aspect of air shower physics which has been neglected so far. PMID:18999734

  15. Stochastic cooling requirements for a muon collider

    SciTech Connect

    Ruggiero, A.G.

    1993-12-31

    The most severe limitation to the muon production for a large-energy muon collider is the short time allowed for cooling the beam to dimensions small enough to provide reasonably high luminosity. The limitation is caused by the short lifetime of the particles. It appears to be desirable to accelerate the beam quickly in very short bunches. This paper describes the requirements of single-pass, fast stochastic cooling for very short bunches. Bandwidth, amplifier gain and Schottky power do not seem to be of major concern. Problems do arise with the ultimate low emittance that can be achieved, the value of which is seriously affected by the front-end noise.

  16. A COMPLETE SCHEME FOR A MUON COLLIDER.

    SciTech Connect

    PALMER,R.B.; BERG, J.S.; FERNOW, R.C.; GALLARDO, J.C.; KIRK, H.G.; ALEXAHIN, Y.; NEUFFER, D.; KAHN, S.A.; SUMMERS, D.

    2007-09-01

    A complete scheme for production, cooling, acceleration, and ring for a 1.5 TeV center of mass muon collider is presented, together with parameters for two higher energy machines. The schemes starts with the front end of a proposed neutrino factory that yields bunch trains of both muon signs. Six dimensional cooling in long-period helical lattices reduces the longitudinal emittance until it becomes possible to merge the trains into single bunches, one of each sign. Further cooling in all dimensions is applied to the single bunches in further helical lattices. Final transverse cooling to the required parameters is achieved in 50 T solenoids.

  17. Energy loss measurement of cosmic ray muons

    NASA Astrophysics Data System (ADS)

    Unger, Joseph

    1993-02-01

    Measurements of energy losses of high energy cosmic ray muons in an ionization chamber are presented. The chamber consists of 16 single gap layers, and the liquid tetra methyl silane (TMS) was used as active medium. The absolute energy loss and the relativistic rise were measured and compared with theoretical calculations. The importance of the measurements within the framework of the cosmic ray experiment KASCADE (German acronym for Karlsruhe Shower Core and Array Detector) are discussed, especially with respect to energy calibration of hadrons and high energy muons above 1 TeV.

  18. FFAG Designs for Muon Collider Acceleration

    SciTech Connect

    Berg, J. Scott

    2014-01-13

    I estimate FFAG parameters for a muon collider with a 70mm longitudinal emittance. I do not discuss the lower emittance beam for a Higgs factory. I produce some example designs, giving only parameters relevant to estimating cost and performance. The designs would not track well, but the parameters of a good design will be close to those described. I compare these cost estimates to those for a fast-ramping synchrotron and a recirculating linear accelerator. I conclude that FFAGs do not appear to be cost-effective for the large longitudinal emittance in a high-energy muon collider.

  19. Rare kaon, muon, and pion decay

    SciTech Connect

    Littenberg, L.

    1998-12-01

    The author discusses the status of and prospects for the study of rare decays of kaons, muons, and pions. Studies of rare kaon decays are entering an interesting new phase wherein they can deliver important short-distance information. It should be possible to construct an alternative unitarity triangle to that determined in the B sector, and thus perform a critical check of the Standard Model by comparing the two. Rare muon decays are beginning to constrain supersymmetric models in a significant way, and future experiments should reach sensitivities which this kind of model must show effects, or become far less appealing.

  20. Prevention des Toxicomanies Aupres des Filles avec des Problemes de Comportement: Effets a Court Terme (Prevention of Drug Addiction in Girls with Behavior Problems: Short-Term Effects).

    ERIC Educational Resources Information Center

    Vitaro, Frank; And Others

    1992-01-01

    This article, written in French, describes and evaluates the first phase of a program to prevent drug addiction among 110 fifth-grade girls with behavior problems in Montreal (Quebec, Canada). Evaluation of the instructional program showed positive results for student knowledge level, attitudes, and behaviors and supported program continuation…

  1. Résection laparoscopique d'une duplication gastrique chez l'adulte: traitement avec succès pour une pathologie rare

    PubMed Central

    Toumi, Omar; Hssine, Hiba Ben; Noomen, Faouzi; Jabra, Sadok Ben; Korbi, Ibtissem; Abdelmoula, Ali; Trimech, Mayada; Mansour, Wafa Ben; Faiez, Boughanmi; Khlifa, Mohamed Ben; Rabah, Hatem; Mahmoudi, Ammar; Nasr, Mohamed; Zouari, Khadija; Saffar, Hammouda; Hamdi, Abdel Aziz

    2015-01-01

    Les duplications de l'appareil digestif sont les malformations congénitales rares qui peuvent toucher tout l'appareil digestive depuis la bouche jusqu’ à l'anus. Certaines duplications sont asymptomatiques et sont diagnostiqués dans la plupart des cas pendant l'enfance. La prise en charge de la duplication gastrique est essentiellement chirurgicale. Le traitement de choix est l'exérèse complète de la duplication gastrique. Les auteurs rapportent un cas inhabituel de duplication gastrique complètement reséquée par laparoscopie. A notre connaissance, ceci est le premier cas d'une duplication gastrique traitée avec succès par laparoscopie dans la littérature Tunisienne. La Résection laparoscopique peut être ajoutée à l'arsenal thérapeutique dans le traitement chirurgical de duplications du tube digestif. PMID:26889326

  2. Symetries et integrabilite des equations aux differences finies

    NASA Astrophysics Data System (ADS)

    Lafortune, Stephane

    2000-09-01

    La présente thèse porte sur l'étude des symétries et des propriétés d'intégrabilité des équations aux différences finies. Dans le chapitre 1, le groupe de symétrie ponctuelle d'un système couplé à deux équations différentielles aux différences est étudié. On montre que dans certains cas, la dimension du groupe peut être infinie. Les équations peuvent décrire l'interaction de deux longues chaînes moléculaires, chacune étant composée d'atomes d'un même type. Dans le chapitre 2, une classe de théories de champs avec interaction exponentielle est introduite. L'interaction dépend de deux matrices de ``couplage'' et est suffisamment générale pour inclure toutes les théories de champs de Toda existant dans la littérature. Les symétries de Lie ponctuelles sont obtenues pour les cas où l'on a un nombre fini, infini ou semi-infini de champs. Une attention spéciale est accordée à la présence de l'invariance conforme. Dans le chapitre 3, nous procédons à la classification et à l'étude d'équations linéarisables. Nous examinons tout d'abord l'équation de Gambier continue qui contient, comme réductions, toutes les équations de deuxième ordre intégrables par linéarisation. Nous introduisons par la suite la forme discrète de cette équation et obtenons les conditions d'intégrabilité à l'aide du confinement des singularités. Nous étudions aussi les différentes réductions du cas discret. De plus, nous obtenons des transformations de Schlesinger pour les équations de Gambier discrète et continue. Dans la dernière partie du chapitre, nous étudions une famille d'équations discrètes du deuxième ordre incluant des équations résolubles par linéarisation. Plusieurs cas intégrables sont obtenus. Dans le cas discret, l'étude de l'intégrabilité est faite à l'aide du confinement des singularités. Dans le chapitre 4, nous étudions un autre critère d'intégrabilité: l'entropie algébrique. Nous montrons que les r

  3. PREFACE: Muon spin rotation, relaxation or resonance

    NASA Astrophysics Data System (ADS)

    Heffner, Robert H.; Nagamine, Kanetada

    2004-10-01

    To a particle physicist a muon is a member of the lepton family, a heavy electron possessing a mass of about 1/9 that of a proton and a spin of 1/2, which interacts with surrounding atoms and molecules electromagnetically. Since its discovery in 1937, the muon has been put to many uses, from tests of special relativity to deep inelastic scattering, from studies of nuclei to tests of weak interactions and quantum electrodynamics, and most recently, as a radiographic tool to see inside heavy objects and volcanoes. In 1957 Richard Garwin and collaborators, while conducting experiments at the Columbia University cyclotron to search for parity violation, discovered that spin-polarized muons injected into materials might be useful to probe internal magnetic fields. This eventually gave birth to the modern field of muSR, which stands for muon spin rotation, relaxation or resonance, and is the subject of this special issue of Journal of Physics: Condensed Matter. Muons are produced in accelerators when high energy protons (generally >500 MeV) strike a target like graphite, producing pions which subsequently decay into muons. Most experiments carried out today use relatively low-energy (~4 MeV), positively-charged muons coming from pions decaying at rest in the skin of the production target. These muons have 100% spin polarization, a range in typical materials of about 180 mg cm-2, and are ideal for experiments in condensed matter physics and chemistry. Negatively-charged muons are also occasionally used to study such things as muonic atoms and muon-catalysed fusion. The muSR technique provides a local probe of internal magnetic fields and is highly complementary to inelastic neutron scattering and nuclear magnetic resonance, for example. There are four primary muSR facilities in the world today: ISIS (Didcot, UK), KEK (Tsukuba, Japan), PSI (Villigen, Switzerland) and TRIUMF (Vancouver, Canada), serving about 500 researchers world-wide. A new facility, JPARC (Tokai, Japan

  4. Acupuncture Au Laser He-Ne: Traitement Des Infections Rhinopharyngees

    NASA Astrophysics Data System (ADS)

    Dussert, Dr.

    1984-03-01

    Mesdames, Messieurs, y a 23 mois, je recevais l'urgence suivante dans mon cabinet medical : 1) Un homme de 53 ans, dyspneioue (cliniquement it etait en Bradypnee expiratoire). Il venait d'être hospitalise 1 mois et avait ete place sous cortisone. Je le fais assoir, et j'irradie avec un laser sur chacun des ganglions stellaires pendant 6 minutes je debloque ce malade qui se met e respirer normalement. 2) Quelques temps apres : C'est un enfant de 7 ans que je regois en crise d'asthme. J'irradie sur chacun des ganglions stellaires pendant 4 minutes une onde laser d'impulsion 6 et en basse freouence. L'enfant voit s'estomper la crise d'asthme. Devant ces deux cas, je decide d'organiser un travail de recherche.

  5. Search for muon EDM with ultra-cold muon beam at J-PARC

    NASA Astrophysics Data System (ADS)

    Mibe, Tsutomu; J-PARC muon g-2/EDM Collaboration

    2014-09-01

    The J-PARC experiment E34 aims to measure the anomalous magnetic moment (g-2) and electric dipole moment (EDM) of the positive muon with a novel technique utilizing an ultra-cold muons accelerated to 300 MeV/ c and a 66 cm-diameter compact muon storage ring without focusing-electric field. This measurement will be complementary to the previous BNL E821 experiment and upcoming FNAL E989 experiment with the muon beam at the magic momentum 3.1 GeV/ c in a 14 m-diameter storage ring. The experiment aims to achieve the sensitivity down to 0.1 ppm for g-2, and 10-21 e . cm for EDM. In this presentation, I'd like to discuss the technical achievements and prospects for realization of the experiment.

  6. Low-energy negative muon interaction with matter

    NASA Astrophysics Data System (ADS)

    Danev, Petar; Adamczak, Andrzej; Bakalov, Dimitar; Mocchiutti, Emiliano; Stoilov, Mihail; Vacchi, Andrea

    2016-03-01

    Using simulated data, obtained with the FLUKA code, we derive empirical regularities about the propagation and stopping of low-energy negative muons in hydrogen and selected solid materials. The results are intended to help the preliminary stages of the set-up design for experimental studies of muon capture and muonic atom spectroscopy. Provided are approximate expressions for the parameters of the the momentum, spatial and angular distribution of the propagating muons. In comparison with the available data on the stopping power and range of muons (with which they agree in the considered energy range) these results have the advantage to also describe the statistical spread of the muon characteristics of interest.

  7. The International Muon Ionization Cooling Experiment: MICE and Neutrino Factories

    NASA Astrophysics Data System (ADS)

    Freemire, Ben

    2010-03-01

    The Muon Ionization Cooling Experiment (MICE) is an accelerator and particle physics experiment aimed at demonstrating the technique of ionization cooling on a beam of muons. Ionization cooling is the process by which muons are sent through an absorbing material, thereby losing energy and decreasing their normalized emittance. The muons are then reaccelerated in the appropriate direction with radio frequency (RF) cavities. This produces an overall reduction in transverse emittance of the muon beam. Ionization cooling could be a key technique in the design of a high intensity Neutrino Factory.

  8. Commissioning of CMS Endcap Muon System

    NASA Astrophysics Data System (ADS)

    Brownell, Elizabeth

    2009-05-01

    This talk is as an overview of the evolution and current state of commissioning work on the CMS endcap muon system. I intend to highlight the progress in operating the detector, some problems encountered and solutions developed, lessons learned in the process, points which still require action to be taken, and data taking results.

  9. Target studies for surface muon production

    NASA Astrophysics Data System (ADS)

    Berg, F.; Desorgher, L.; Fuchs, A.; Hajdas, W.; Hodge, Z.; Kettle, P.-R.; Knecht, A.; Lüscher, R.; Papa, A.; Rutar, G.; Wohlmuther, M.

    2016-02-01

    Meson factories are powerful drivers of diverse physics programs. With beam powers already in the MW-regime attention has to be turned to target and beam line design to further significantly increase surface muon rates available for experiments. For this reason we have explored the possibility of using a neutron spallation target as a source of surface muons by performing detailed Geant4 simulations with pion production cross sections based on a parametrization of existing data. While the spallation target outperforms standard targets in the backward direction by more than a factor 7 it is not more efficient than standard targets viewed under 90°. Not surprisingly, the geometry of the target plays a large role in the generation of surface muons. Through careful optimization, a gain in surface muon rate of between 30% and 60% over the standard "box-like" target used at the Paul Scherrer Institute could be achieved by employing a rotated slab target. An additional 10% gain could also be possible by utilizing novel target materials such as, e.g., boron carbide.

  10. Muon Collider Machine-Detector Interface

    SciTech Connect

    Mokhov, Nikolai V.; /Fermilab

    2011-08-01

    In order to realize the high physics potential of a Muon Collider (MC) a high luminosity of {mu}{sup +}{mu}{sup -}-collisions at the Interaction Point (IP) in the TeV range must be achieved ({approx}10{sup 34} cm{sup -2}s{sup -1}). To reach this goal, a number of demanding requirements on the collider optics and the IR hardware - arising from the short muon lifetime and from relatively large values of the transverse emittance and momentum spread in muon beams that can realistically be obtained with ionization cooling should be satisfied. These requirements are aggravated by limitations on the quadrupole gradients as well as by the necessity to protect superconducting magnets and collider detectors from muon decay products. The overall detector performance in this domain is strongly dependent on the background particle rates in various sub-detectors. The deleterious effects of the background and radiation environment produced by the beam in the ring are very important issues in the Interaction Region (IR), detector and Machine-Detector Interface (MDI) designs. This report is based on studies presented very recently.

  11. ICOOL: A TOOL FOR MUON COLLIDER SIMULATIONS.

    SciTech Connect

    FERNOW,R.C.

    2001-09-28

    Current ideas for designing neutrino factories [ 1,2] and muon colliders [3] require unique configurations of fields and materials to prepare the muon beam for acceleration. This so-called front end system must accomplish the goals of phase rotation, bunching and cooling. We have continued the development of a 3-D tracking code, ICOOL [4], for examining possible muon collider front end configurations. A system is described in terms of a series of longitudinal regions with associated material and field properties. The tracking takes place in a coordinate system that follows a reference orbit through the system. The code takes into account decays and interactions of {approx}50-500 MeV/c muons in matter. Material geometry regions include cylinders and wedges. A number of analytic models are provided for describing the field configurations. Simple diagnostics are built into the code, including calculation of emittances and correlations, longitudinal traces, histograms and scatter plots. A number of auxiliary codes can be used for pre-processing, post-processing and optimization.

  12. Neutrino masses, Majorons, and muon decay

    SciTech Connect

    Santamaria, A.; Bernabeu, J.; Pich, A.

    1987-09-01

    The contributions to the parameters xi, delta, rho, and eta in muon decay coming from double Majoron emission, Majorana neutrino masses, and effects of charged scalars are evaluated in the scalar-triplet model. The relevance of these effects for planned experiments is discussed.

  13. Multi-muon events at CDF

    SciTech Connect

    Ptochos, F.; /Cyprus U.

    2009-07-01

    We report a study of multi-muon events produced at the Fermilab Tevatron collider and recorded by the CDF II detector. In a data set acquired with a dedicated dimuon trigger and corresponding to an integrated luminosity of 2100 pb{sup -1}, we isolate a significant sample of events in which at least one of the identified muons has large impact parameter and is produced outside the beam pipe of radius 1.5 cm. We are unable to fully account for the number and properties of the events through standard model processes in conjunction with our current understanding of the CDF II detector, trigger and event reconstruction. Several topological and kinematic properties of these events are also presented. In contrast, the production cross section and kinematics of events in which both muon candidates are produced inside the beam pipe are successfully modeled by known QCD processes which include heavy flavor production. The presence of these anomalous multi-muon events offers a plausible resolution to long-standing inconsistencies related to b{bar b} production and decay.

  14. Gamma rays from muons from WIMPs: Implementation of radiative muon decays for dark matter analyses

    NASA Astrophysics Data System (ADS)

    Scaffidi, Andre; Freese, Katherine; Li, Jinmian; Savage, Christopher; White, Martin; Williams, Anthony G.

    2016-06-01

    Dark matter searches in gamma ray final states often make use of the fact that photons can be produced from final state muons. Modern Monte Carlo generators and dark matter codes include the effects of final state radiation from muons produced in the dark matter annihilation process itself, but neglect the O (1 %) radiative correction that arises from the subsequent muon decay. After implementing this correction we demonstrate the effect that it can have on dark matter phenomenology by considering the case of dark matter annihilation to four muons via scalar mediator production. We first show that the AMS-02 positron excess can no longer easily be made consistent with this final state once the Fermi-LAT dwarf limits are calculated with the inclusion of radiative muon decays, and we next show that the Fermi-LAT galactic center gamma excess can be improved with this final state after inclusion of the same effect. We provide code and tables for the implementation of this effect in the popular dark matter code micrOMEGAs, providing a solution for any model producing final state muons.

  15. Corrections for temperature effect for ground-based muon hodoscopes

    NASA Astrophysics Data System (ADS)

    Dmitrieva, A. N.; Kokoulin, R. P.; Petrukhin, A. A.; Timashkov, D. A.

    2011-01-01

    Influence of atmospheric temperature on muon flux at sea level is considered. Results of calculations of muon spectrum for normal atmospheric conditions, differential temperature coefficients (DTC) for muons at different zenith angles and threshold energies are presented. In calculations, a six-layer stationary spherical model of atmosphere is used, contributions of both pions and kaons as well as dependence of muon energy loss on muon energy are taken into account. Comparison of muon spectrum calculations and experimental data in a wide range of zenith angles and momentums shows a good agreement. Comparison of results of DTC calculations with results of earlier works exhibits only qualitative agreement; possible sources of differences are analyzed. Some practical questions of the use of DTC for muon hodoscope data analysis are discussed.

  16. Identification of Low PT Muon with the Atlas Tile Calorimeter

    NASA Astrophysics Data System (ADS)

    Usai, G.

    2005-02-01

    A method for the identification of muons with the ATLAS Tile Calorimeter is presented and its efficiency and mis-tagging fraction are discussed. It is demonstrated that the Tile Calorimeter can identify muons with good efficiency down to 2 GeV/c transverse momentum, where the stand-alone Muon Spectrometer has zero efficiency. This kinematic region is important for study of B meson physics and in the particular for the CP violating decay channels. The effectiveness of this method is tested, in particular, in the case of bbar {b} events at low LHC luminosity (1033cm-1s-2) with full simulation of experimental conditions. The muon identification with the Tile Calorimeter is fast and can be used for muon selection at the trigger level. A method of exploiting the information available in other ATLAS sub-detectors in order to reduce spurious muon-tag and measure the candidate muon momentum is discussed.

  17. Novel approach to imaging by cosmic-ray muons

    NASA Astrophysics Data System (ADS)

    Bikit, Istvan; Mrdja, Dusan; Bikit, Kristina; Slivka, Jaroslav; Jovancevic, Nikola; Oláh, László; Hamar, Gergő; Varga, Dezső

    2016-03-01

    Cosmic-ray muons can be used for imaging of large structures, or high-density objects with high atomic number. The first task can be performed by measurement of muon absorption within very thick material layers, while the second approach is based on muon multiple scattering. However, the muon imaging of small structures with low atomic number and density was not yet solved appropriately. Here we show the first results of cosmic-ray muon imaging of small objects made of elements of low atomic number. This novel approach includes detection of secondary particles produced by muons, which were not used at all in previous muon imaging methods. Thus, the list of elements, as well as the range of dimensions of objects which can be imaged are significantly expanded.

  18. Design and commissioning of a high magnetic field muon spin relaxation spectrometer at the ISIS pulsed neutron and muon source.

    PubMed

    Lord, J S; McKenzie, I; Baker, P J; Blundell, S J; Cottrell, S P; Giblin, S R; Good, J; Hillier, A D; Holsman, B H; King, P J C; Lancaster, T; Mitchell, R; Nightingale, J B; Owczarkowski, M; Poli, S; Pratt, F L; Rhodes, N J; Scheuermann, R; Salman, Z

    2011-07-01

    The high magnetic field (HiFi) muon instrument at the ISIS pulsed neutron and muon source is a state-of-the-art spectrometer designed to provide applied magnetic fields up to 5 T for muon studies of condensed matter and molecular systems. The spectrometer is optimised for time-differential muon spin relaxation studies at a pulsed muon source. We describe the challenges involved in its design and construction, detailing, in particular, the magnet and detector performance. Commissioning experiments have been conducted and the results are presented to demonstrate the scientific capabilities of the new instrument. PMID:21806196

  19. Design and commissioning of a high magnetic field muon spin relaxation spectrometer at the ISIS pulsed neutron and muon source

    SciTech Connect

    Lord, J. S.; McKenzie, I.; Baker, P. J.; Cottrell, S. P.; Giblin, S. R.; Hillier, A. D.; Holsman, B. H.; King, P. J. C.; Nightingale, J. B.; Pratt, F. L.; Rhodes, N. J.; Blundell, S. J.; Lancaster, T.; Good, J.; Mitchell, R.; Owczarkowski, M.; Poli, S.; Scheuermann, R.; Salman, Z.

    2011-07-15

    The high magnetic field (HiFi) muon instrument at the ISIS pulsed neutron and muon source is a state-of-the-art spectrometer designed to provide applied magnetic fields up to 5 T for muon studies of condensed matter and molecular systems. The spectrometer is optimised for time-differential muon spin relaxation studies at a pulsed muon source. We describe the challenges involved in its design and construction, detailing, in particular, the magnet and detector performance. Commissioning experiments have been conducted and the results are presented to demonstrate the scientific capabilities of the new instrument.

  20. Prévalence des cervicalgies et douleurs des membres supérieures chez les utilisateurs d'ordinateur en milieu professionnel à Casablanca (Maroc)

    PubMed Central

    Seknaji, Nawal; Rachidi, Wafaa; Hassoune, Samira; Janani, Saadia; Nani, Samira; Maaroufi, Abderrahmane; Mkinsi, Ouafaa

    2013-01-01

    Introduction Les cervicalgies et douleurs du membre supérieur (CDMS) affectent des millions d'utilisateurs d'ordinateurs dans les pays développés. L'objectif de ce travail était de déterminer la prévalence des cervicalgies et douleurs du membre supérieur (CDMS) à Casablanca et identifier les différents facteurs de risque qui y sont impliqués, afin de définir les sous-groupes à haut risque, et d’établir des plans d'intervention efficaces. Méthodes Il s'agit d'une étude transversale, menée chez 118 employés de bureau francophones et utilisant l'ordinateur, à Casablanca. Les données ont été collectées de Décembre 2011 à Juin 2012, en utilisant la version française d'un questionnaire validé: Maastricht-Upper-extremity-Questionnaire. Résultats 118 utilisateurs d'ordinateur en milieu professionnel ont été recrutés. Parmi les employés enquêtés, 93% ont rapporté des CDMS localisées au moins à un site. Les plaintes les plus fréquemment rapportées étaient les douleurs des épaules et les cervicalgies (48,3% et 46,6% respectivement). Nous n'avons pas remarqué de différence significative des fréquences des douleurs selon le genre. Nos résultats concordent avec les données de la littérature où il existe un certain consensus quant à l'impact des mauvaises conditions ergonomiques sur les troubles musculo-squelettiques du membre supérieur en milieu professionnel. De même, les études récentes examinant les effets combinés et/ou interactifs tant des facteurs biomécaniques/physiques que de facteurs psychosociaux professionnels vont de pair avec nos résultats. Conclusion Il en ressort que les stratégies d'intervention visant à réduire les CDMS doivent agir essentiellement sur 3 volets, le premier correspond à l'amélioration et la sensibilisation quant au respect des conditions ergonomiques, le second concerne l'amélioration des conditions psychosociales. Enfin le troisième volet vise la rationalisant de la demande de

  1. Volcanoes muon imaging using Cherenkov telescopes

    NASA Astrophysics Data System (ADS)

    Catalano, O.; Del Santo, M.; Mineo, T.; Cusumano, G.; Maccarone, M. C.; Pareschi, G.

    2016-01-01

    A detailed understanding of a volcano inner structure is one of the key-points for the volcanic hazards evaluation. To this aim, in the last decade, geophysical radiography techniques using cosmic muon particles have been proposed. By measuring the differential attenuation of the muon flux as a function of the amount of rock crossed along different directions, it is possible to determine the density distribution of the interior of a volcano. Up to now, a number of experiments have been based on the detection of the muon tracks crossing hodoscopes, made up of scintillators or nuclear emulsion planes. Using telescopes based on the atmospheric Cherenkov imaging technique, we propose a new approach to study the interior of volcanoes detecting of the Cherenkov light produced by relativistic cosmic-ray muons that survive after crossing the volcano. The Cherenkov light produced along the muon path is imaged as a typical annular pattern containing all the essential information to reconstruct particle direction and energy. Our new approach offers the advantage of a negligible background and an improved spatial resolution. To test the feasibility of our new method, we have carried out simulations with a toy-model based on the geometrical parameters of ASTRI SST-2M, i.e. the imaging atmospheric Cherenkov telescope currently under installation onto the Etna volcano. Comparing the results of our simulations with previous experiments based on particle detectors, we gain at least a factor of 10 in sensitivity. The result of this study shows that we resolve an empty cylinder with a radius of about 100 m located inside a volcano in less than 4 days, which implies a limit on the magma velocity of 5 m/h.

  2. Résultats du traitement du synovialosarcome des members

    PubMed Central

    Lukulunga, Loubet Unyendje; Moussa, Abdou Kadri; Mahfoud, Mustapha; El Bardouni, Ahmed; Ismail, Farid; Kharmaz, Mohammed; Berrada, Mohamed Saleh; El Yaacoubi, Moradh

    2014-01-01

    Les synovialosarcomes, sarcomes de haut grade, sont de diagnostic tardif et le traitement est complexe et onéreux, nécessitant la mise en œuvre d'une équipe pluridisciplinaire. Le but de ce travail était d'apprécier les résultats de l'association de la chirurgie à la radio chimiothérapie des synovialosarcomes des membres. Il s'agissait d'une étude rétrospective portant sur des patients présentant de synovialosarcomes des membres pris en charge dans le service de chirurgie orthopédique et traumatologique du CHU Ibn SINA de Rabat allant de Janvier 2006 à Décembre 2011 (6 ans). Nous avons inclus les malades présentant de synovialosarcomes des membres dont la clinique et l'imagerie médicale étaient en faveur, confirmés par l'examen anatomopathologique et la prise en charge effectuée dans le service. Les patients ont été revus avec un recul moyen de 3 ans. Nous n'avons pas retenu les patients dont les dossiers étaient incomplets, perdus de vue. Nous avons apprécié les résultats selon les critères carcinologiques et le score MSTS (Musculoskeletal Tumor Society). La saisie et l'analyse des données ont été faites sur le logiciel SPSS Stastic 17.0 Nous avons colligé 20 cas de synovialosarcome des membres dans le Service de Chirurgie Orthopédique et Traumatologique au CHU Ibn SINA de Rabat Le sexe masculin a prédominé avec 65% (n = 13) avec un sex ratio 1,85. L’âge moyen a été de 42,6 ans avec des extrêmes allant de 20 ans et 70 ans. Notre délai moyen de consultation était de 14,42 mois. Tous les malades ont consulté pour une tuméfaction dans 100% (localisée au membre inférieur dans 65% (n = 13), membre supérieur dans 35% (n = 7). La douleur était associée à la tuméfaction dans 55% (n = 11), quant à l'altération de l’état général et l'ulcération de la masse, elles ont été notées dans 3 cas chacune. Nous avons réalisé un bilan d'imagerie médicale comprenant: radiographie standard, échographie, écho doppler

  3. Integration des sciences et de la langue: Creation et experimentation d'un modele pedagogique pour ameliorer l'apprentissage des sciences en milieu francophone minoritaire

    NASA Astrophysics Data System (ADS)

    Cormier, Marianne

    Les faibles resultats en sciences des eleves du milieu francophone minoritaire, lors d'epreuves au plan national et international, ont interpelle la recherche de solutions. Cette these avait pour but de creer et d'experimenter un modele pedagogique pour l'enseignement des sciences en milieu linguistique minoritaire. En raison de la presence de divers degres de francite chez la clientele scolaire de ce milieu, plusieurs elements langagiers (l'ecriture, la discussion et la lecture) ont ete integres a l'apprentissage scientifique. Nous avions recommande de commencer le processus d'apprentissage avec des elements langagiers plutot informels (redaction dans un journal, discussions en dyades...) pour progresser vers des activites langagieres plus formelles (redaction de rapports ou d'explications scientifiques). En ce qui a trait a l'apprentissage scientifique, le modele preconisait une demarche d'evolution conceptuelle d'inspiration socio-constructiviste tout en s'appuyant fortement sur l'apprentissage experientiel. Lors de l'experimentation du modele, nous voulions savoir si celui-ci provoquait une evolution conceptuelle chez les eleves, et si, simultanement, le vocabulaire scientifique de ces derniers s'enrichissait. Par ailleurs, nous cherchions a comprendre comment les eleves vivaient leurs apprentissages dans le cadre de ce modele pedagogique. Une classe de cinquieme annee de l'ecole de Grande-Digue, dans le Sud-est du Nouveau-Brunswick, a participe a la mise a l'essai du modele en etudiant les marais sales locaux. Lors d'entrevues initiales, nous avons remarque que les connaissances des eleves au sujet des marais sales etaient limitees. En effet, s'ils etaient conscients que les marais etaient des lieux naturels, ils ne pouvaient pas necessairement les decrire avec precision. Nous avons egalement constate que les eleves utilisaient surtout des mots communs (plantes, oiseaux, insectes) pour decrire le marais. Les resultats obtenus indiquent que les eleves ont

  4. Frontiers of muon spectroscopy—25 years of muon science at ISIS

    NASA Astrophysics Data System (ADS)

    Cottrell, Stephen

    2013-12-01

    The ISIS muon source developed with support from the European Community (EC) and groups at Grenoble, Parma, Uppsala and Munich in the late 1980s, with a single instrument providing many scientists with their first opportunity to explore the unique capabilities of muon spectroscopy. The timing was opportune, as the muon technique was making an important contribution to the study of the then recently discovered cuprate high T c superconductors. The ISIS user community developed rapidly over subsequent years, with the technique finding a broad range of applications in condensed matter physics, materials science and chemistry. The single instrument was hugely oversubscribed, and the importance of the technique was recognized in 1993 with a further grant from the EC to develop the triple beamline facility that is currently available at ISIS. During 2009 the suite of spectrometers available at the facility received a major upgrade, with the Science and Technology Facilities Council funding the development of a 5 T high field instrument that has enabled entirely new applications of muon spectroscopy to be explored. The facility continues to flourish, with a strong user community exploiting the technique to support research across an increasingly broad range of subject areas. Condensed matter science continues to be a major area of interest, with applications including semiconductors and dielectrics, superconductors, magnetism, interstitial diffusion and charge transport. Recently, however, molecular science and radical chemistry have become prominent in the ISIS programme, applications where the availability of high magnetic fields is frequently vital to the success of the experiments. For ISIS, 23 March 2012 marked a significant milestone, it being 25 years since muons were first produced at the facility for research in condensed matter and molecular science. To celebrate, the ISIS muon group organized a science symposium with the theme 'Frontiers of Muon Spectroscopy

  5. PREFACE: Muon spin rotation, relaxation or resonance

    NASA Astrophysics Data System (ADS)

    Heffner, Robert H.; Nagamine, Kanetada

    2004-10-01

    To a particle physicist a muon is a member of the lepton family, a heavy electron possessing a mass of about 1/9 that of a proton and a spin of 1/2, which interacts with surrounding atoms and molecules electromagnetically. Since its discovery in 1937, the muon has been put to many uses, from tests of special relativity to deep inelastic scattering, from studies of nuclei to tests of weak interactions and quantum electrodynamics, and most recently, as a radiographic tool to see inside heavy objects and volcanoes. In 1957 Richard Garwin and collaborators, while conducting experiments at the Columbia University cyclotron to search for parity violation, discovered that spin-polarized muons injected into materials might be useful to probe internal magnetic fields. This eventually gave birth to the modern field of muSR, which stands for muon spin rotation, relaxation or resonance, and is the subject of this special issue of Journal of Physics: Condensed Matter. Muons are produced in accelerators when high energy protons (generally >500 MeV) strike a target like graphite, producing pions which subsequently decay into muons. Most experiments carried out today use relatively low-energy (~4 MeV), positively-charged muons coming from pions decaying at rest in the skin of the production target. These muons have 100% spin polarization, a range in typical materials of about 180 mg cm-2, and are ideal for experiments in condensed matter physics and chemistry. Negatively-charged muons are also occasionally used to study such things as muonic atoms and muon-catalysed fusion. The muSR technique provides a local probe of internal magnetic fields and is highly complementary to inelastic neutron scattering and nuclear magnetic resonance, for example. There are four primary muSR facilities in the world today: ISIS (Didcot, UK), KEK (Tsukuba, Japan), PSI (Villigen, Switzerland) and TRIUMF (Vancouver, Canada), serving about 500 researchers world-wide. A new facility, JPARC (Tokai, Japan

  6. Studies on muon tomography for archaeological internal structures scanning

    NASA Astrophysics Data System (ADS)

    Gómez, H.; Carloganu, C.; Gibert, D.; Jacquemier, J.; Karyotakis, Y.; Marteau, J.; Niess, V.; Katsanevas, S.; Tonazzo, A.

    2016-05-01

    Muon tomography is a potential non-invasive technique for internal structure scanning. It has already interesting applications in geophysics and can be used for archaeological purposes. Muon tomography is based on the measurement of the muon flux after crossing the structure studied. Differences on the mean density of these structures imply differences on the detected muon rate for a given direction. Based on this principle, Monte Carlo simulations represent a useful tool to provide a model of the expected muon rate and angular distribution depending on the composition of the studied object, being useful to estimate the expected detected muons and to better understand the experimental results. These simulations are mainly dependent on the geometry and composition of the studied object and on the modelling of the initial muon flux at surface. In this work, the potential of muon tomography in archaeology is presented and evaluated with Monte Carlo simulations by estimating the differences on the muon rate due to the presence of internal structures and its composition. The influence of the chosen muon model at surface in terms of energy and angular distributions in the final result has been also studied.

  7. Imaging a vertical shaft from a tunnel using muons

    NASA Astrophysics Data System (ADS)

    Bonal, N.; Preston, L. A.; Dorsey, D. J.; Schwellenbach, D.; Green, A.; Smalley, D.

    2015-12-01

    We use muon technology to image a vertical shaft from a tunnel. The density of the materials through which cosmic ray muons pass influences the flux of muons because muons are more attenuated by higher density material. Additionally, muons can travel several kilometers allowing measurements through deep rock. Density maps are generated from muon flux measurements to locate subsurface features like tunnel structures and ore bodies. Additionally, muon data can be jointly inverted with other data such as gravity and seismic to produce higher quality earth models than produced from a single method. We collected several weeks of data in a tunnel to image a vertical shaft. The minimum length of rock between the vertical shaft and the detector is 120 meters and the diameter of the vertical shaft is 4.6 meters. The rock the muons traveled through consists of Tertiary age volcanic tuff and steeply dipping, small-displacement faults. Results will be presented for muon flux in the tunnel and Monte-Carlo simulations of this experiment. Simulations from both GEANT4 (Geometry And Tracking version 4) and MCNP6 (Monte-Carlo N-Particle version 6) models will be compared. The tunnel overburden from muon measurements is also estimated and compared with actual the overburden. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  8. Relation entre les caractéristiques des table-bancs et les mesures anthropométriques des écoliers au Benin

    PubMed Central

    Falola, Stève Marjelin; Gouthon, Polycarpe; Falola, Jean-Marie; Fiogbe, Michel Armand; Nigan, Issiako Bio

    2014-01-01

    Introduction Le mobilier scolaire et la posture assise en classe sont souvent impliqués dans l'apparition des douleurs rachidiennes, influant de fait sur la qualité des tâches réalisées par les apprenants. Aucune étude n'a encore vérifié le degré d'adéquation entre les caractéristiques du mobilier et celles des écoliers au Bénin. L'objectif de cette étude transversale est donc de déterminer la relation entre les dimensions des table-bancs utilisées en classe et les mesures anthropométriques des écoliers au Bénin. Methods Elle a été réalisée avec un échantillon probabiliste de 678 écoliers, âgés de 4 à 17 ans. Les mesures anthropométriques des écoliers et les mensurations relatives aux longueurs, largeurs et hauteurs des table-bancs ont été mesurées, puis intégrées aux équations proposées dans la littérature. Les pourcentages des valeurs situées hors des limitesacceptables, dérivées de l'application des équations ont été calculés. Results La largeur et la hauteur des table-bancs utilisées par les écoliers étaient plus élevées (p < 0,05) que les valeurs de référence recommandées par les structures officielles de contrôle et de production des mobiliers scolaires au Bénin. Quel que soit le sexe, il y avait une inadéquation entre la largeur du banc et la longueur fesse-poplité, puis entre la hauteur de la table et la distance coude-bancdes écoliers. Conclusion Les résultats suggèrent de prendre en compte l’évolution des mesures anthropométriques des écoliers dans la confection des table-bancs, afin de promouvoir de bonnes postures assises en classe et de réduire le risque de troubles du rachis. PMID:25317232

  9. A Compact and High Performance Muon Capture Channel for Muon Accelerators

    SciTech Connect

    Stratakis, D.; Gallardo, J.; Palmer, R.B.

    2011-03-28

    It is widely believed that a neutrino factory would deliver unparallel performance in studying neutrino mixing and would provide tremendous sensitivity to new physics in the neutrino sector. Here we will describe and simulate the front-end of the neutrino factory system, which plays critical role in determining the number of muons that can be accepted by the downstream accelerators. In this system, a proton bunch on a target creates secondaries that drift into a capture transport channel. A sequence of rf cavities forms the resulting muon beams into strings of bunches of differing energies, aligns the bunches to nearly equal central energies, and initiates ionization cooling. For this, the muon beams are transported through sections containing high-gradient cavities and strong focusing solenoids. In this paper we present results of optimization and variation studies toward obtaining the maximum number of muons for a neutrino factory by using a compact transport channel. It has been suggested computationally and experimentally that the maximum achievable gradient is enhanced by introducing an external magnetic field at right angles to the rf electric field since it suppresses field-emission processes. Here, we have discussed a possible scheme for extending the concept of magnetic insulation to capture, transport, and cool muons in a neutrino factory. We incorporated this idea into a new lattice design where the rf cavities are shaped so that their walls were tangential to the magnetic-field lines. We showed that, with magnetic insulation, the field-emitted electrons impact the cavity surface with energies four orders-of-magnitude less than in conventional pillbox cavities; consequently, damage from field-emission is suppressed significantly. While demanding in terms of power requirements, this neutrino factory lattice showed satisfactory performance in both cooling and collecting the accepted muons within the requirements for the IDSNF. Optimizations were also made

  10. Jumeaux conjoints au niveau d’une omphalocèle commune avec extrophie cloacale et ambigüité sexuelle

    PubMed Central

    Boujoual, Majdouline; Madani, Hamid; Benhaddou, Housain; Belahcen, Mohamed

    2014-01-01

    Les jumeaux conjoints sont considérés comme étant une complication rare et grave des grossesses monozygotes. Le diagnostic anténatal permet de définir avec précision les structures communes, de rechercher une anomalie congénitale associée, d'organiser l´accouchement et la prise en charge néonatale. Nous présentons un cas rare de jumeaux conjoints dont la fusion se situait au niveau d'une omphalocèle commune associée à une extrophie cloacale, ambiguïté sexuelle et pieds bots. Le diagnostic a été méconnu pendant la grossesse, ce qui a engendré une dystocie lors de l'accouchement. L'issue a été fatale malgré une tentative de séparation et des mesures de réanimation. Ce cas illustre la difficulté liée d'une part à la méconnaissance du diagnostic, d'autre part au caractère urgent de la césarienne et de la séparation chirurgicale. PMID:25170387