@prefix dcat: <http://www.w3.org/ns/dcat#> .
@prefix dct: <http://purl.org/dc/terms/> .
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix vcard: <http://www.w3.org/2006/vcard/ns#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

<https://rec.harvest-normandie.data4citizen.com/dataset/oai-hal-tel-00936039v1> a dcat:Dataset ;
    dct:description """
              The Gravitational Behaviour of Antihydrogen at Rest experiment - GBAR - is designed to perform a direct measurement of the weak equivalence principle on antimatter by measuring the acceleration (gbar) of antihydrogen atoms in free fall. Its originality is to produce Hbar+ ions and use sympathetic cooling to achieve µK temperature. Hbar+ ions are produced by the reactions : pbar + Ps -> Hbar + e-, and Hbar + Ps -> Hbar+ + e-, where pbar is an antiproton, Ps stands for positronium (the bound-state of a positron and an electron), Hbar is the antihydrogen and Hbar+ the antiion associated. To produce enough Ps atoms, 2x10^10 positrons must be impinged on a porous SiO2 target within 100ns. Such an intense flux requires the accumulation (collection and cooling) of the positrons in a particle trap. This thesis describes the injector being commissioned at CEA Saclay for GBAR. It consists of a Penning-Malmberg trap (moved from RIKEN) fed by a slow positron beam. A 4.3MeV linear accelerator shooting electrons on a tungsten target produces the pulsed positron beam, which is moderated by a multi-grid tungsten moderator. The slow positron flux is 10^4 e+/pulse, or 2x10^6 e+/s at 200Hz. This work presents the first ever accumulation of low-energy positrons produced by an accelerator (rather than a radioactive source) and their cooling by a prepared reservoir of 2x10^10 cold electrons.
            """ ;
    dct:identifier "NNT: 2013PA112352" ;
    dct:issued "2026-05-07T06:37:51.536626"^^xsd:dateTime ;
    dct:language "fr" ;
    dct:modified "2026-05-07T06:37:51.536631"^^xsd:dateTime ;
    dct:publisher <https://rec.harvest-normandie.data4citizen.com/organization/cce9db95-46d9-4dc2-84b6-764215d0a002> ;
    dct:title "Trapping and accumulation of positrons from a pulsed beam produced by a linear accelerator for gravitationnal interaction of antimatter study." ;
    dcat:contactPoint [ a vcard:Organization ;
            vcard:fn "CCSD" ] ;
    dcat:distribution <https://rec.harvest-normandie.data4citizen.com/dataset/oai-hal-tel-00936039v1/resource/961369b9-0973-4c48-8bb9-178bbaa619dc> ;
    dcat:keyword "antimatiere",
        "antimatter",
        "faisceau-pulse",
        "infoeu-reposemanticsdoctoralthesis",
        "nonneutral-plasma",
        "penning-malmberg-trap",
        "physcondcm-genphysics-physicscondensed-matter-cond-matother-cond-matother",
        "piege-de-penning-malmberg",
        "plasma-non-neutre",
        "positon",
        "positron",
        "pulsed-beam",
        "theses" ;
    dcat:landingPage <https://theses.hal.science/tel-00936039> .

<https://rec.harvest-normandie.data4citizen.com/dataset/oai-hal-tel-00936039v1/resource/961369b9-0973-4c48-8bb9-178bbaa619dc> a dcat:Distribution ;
    dct:format "HTML" ;
    dct:issued "2026-05-07T06:37:51.547140"^^xsd:dateTime ;
    dct:modified "2026-05-07T06:37:51.520558"^^xsd:dateTime ;
    dct:title "Trapping and accumulation of positrons from a pulsed beam produced by a linear accelerator for gravitationnal interaction of antimatter study." ;
    dcat:accessURL <https://theses.hal.science/tel-00936039> .

<https://rec.harvest-normandie.data4citizen.com/organization/cce9db95-46d9-4dc2-84b6-764215d0a002> a foaf:Agent ;
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<https://theses.hal.science/tel-00936039> a foaf:Document .