HARPO: a TPC as a gamma-ray telescope and polarimeter

A gas Time Projection Chamber can be used for gamma-ray astronomy with excellent angular-precision and sensitivity to faint sources, and for polarimetry, through the measurement of photon conversion to $e^+e^-$ pairs. We present the expected performance in simulations and the recent development of a demonstrator for tests in a polarized photon beam.Comment: SPIE Astronomical Telescopes + Instrumentation, Ultraviolet to gamma ray, Montr\'eal, Canada 2014. v2: note added in proof. Copyright 2014 SPIE. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibite

A Time Projection Chamber with GEM-Based Readout

For the International Large Detector concept at the planned International Linear Collider, the use of time projection chambers (TPC) with micro-pattern gas detector readout as the main tracking detector is investigated. In this paper, results from a prototype TPC, placed in a 1 T solenoidal field and read out with three independent GEM-based readout modules, are reported. The TPC was exposed to a 6 GeV electron beam at the DESY II synchrotron. The efficiency for reconstructing hits, the measurement of the drift velocity, the space point resolution and the control of field inhomogeneities are presented.Comment: 22 pages, 19 figure

Capture de Coelonia solani (Boisduval, 1833) à l'île de la Réunion. Description de la chenille et de sa chrysalide (Lepidoptera, Sphingidae)

Capture of Coelonia solani (Boisduval, 1833) in the island of Réunion. Description of the caterpillar and the chrysalid (Lepidoptera, Sphingidae). A caterpillar of Coelonia solani (Boisduval, 1833) was discovered on Clerodendrum heterophyllum (Poiret) R. Br. an endemic plant of La Reunion and Mauritius islands. It is the first record of this Sphingidae in La Reunion island since 1862 and this host-plant was hitherto unknown. A description of larva and pupa is given ; their characteristics differ from those appearing in Boisduval diagnosis.Une chenille de Coelonia solani (Boisduval, 1833) a été découverte lors de nos prospections en milieux semi-xérophiles sur la Verbénacée Clerodendrum heterophyllum (Poiret) R. Br., endémique de la Réunion et de Maurice. Cette espèce n'avait pas été observée dans 111e depuis 1862 et cet arbrisseau n'était jusqu'alors pas connu comme plante-hôte de ce Sphinx. L'imago obtenu à la suite de l'élevage de la chenille a permis d'identifier l'espèce et de montrer que la larve et sa chrysalide présentaient des caractères différents de ceux figurant dans la description de Boisduval (1833), remettant en cause ses diagnoses larvaire et nymphale.Attié Marc, Morel Gilles. Capture de Coelonia solani (Boisduval, 1833) à l'île de la Réunion. Description de la chenille et de sa chrysalide (Lepidoptera, Sphingidae). In: Bulletin de la Société entomologique de France, volume 102 (5), décembre 1997. pp. 413-418

Description et éléments d'écologie d'un nouvel Hémiptère de la Réunion : <i>Insulisia borbonica</i> n. gen, n. sp. (Fulgoromorpha, Meenoplidae)

International audienceInsulisia borbonica n. gen., n. sp. is described from the island of Réunion and aspects of its ecology are detailed. This previously unknown hemipteran taxon belongs to the subfamily Kermesiinae and is closely related to the genus Eponisia, so far know only from Taiwan.Une forme inédite de la Réunion, de la sous-famille des Kermesiinae, voisine des Eponisia de Taïwan, est décrite, dans un genre nouveau