title: A diamond based neutron spectrometer for diagnostics of deuterium-tritium fusion plasmas.
abstract: Single crystal Diamond Detectors (SDD) are being increasingly exploited for neutron diagnostics in high power fusion devices, given their significant radiation hardness and high energy resolution capabilities. The geometrical efficiency of SDDs is limited by the size of commercially available crystals, which is often smaller than the dimension of neutron beams along collimated lines of sight in tokamak devices. In this work, we present the design and fabrication of a 14 MeV neutron spectrometer consisting of 12 diamond pixels arranged in a matrix, so to achieve an improved geometrical efficiency. Each pixel is equipped with an independent high voltage supply and read-out electronics optimized to combine high energy resolution and fast signals (<30 ns), which are essential to enable high counting rate (>1 MHz) spectroscopy. The response function of a prototype SDD to 14 MeV neutrons has been measured at the Frascati Neutron Generator by observation of the 8.3 MeV peak from the (12)C(n, α)(9)Be reaction occurring between neutrons and (12)C nuclei in the detector. The measured energy resolution (2.5% FWHM) meets the requirements for neutron spectroscopy applications in deuterium-tritium plasmas.
authors.affiliation: University of Milano Bicocca, Piazza della Scienza 3, Milano, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Cazzaniga
authors.affiliation: University of Milano Bicocca, Piazza della Scienza 3, Milano, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Nocente
authors.affiliation: University of Milano Bicocca, Piazza della Scienza 3, Milano, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Rebai
authors.affiliation: Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, via Roberto Cozzi 53, Milano, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Tardocchi
authors.affiliation: CNR-ISM, Research Area Roma 1, Via Salaria km 29.300, 00015-Monterotondo Scalo (Rm), Italy.
authors.forename: P
authors.initials: P
authors.lastname: Calvani
authors.affiliation: Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, via Roberto Cozzi 53, Milano, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Croci
authors.affiliation: University of Milano Bicocca, Piazza della Scienza 3, Milano, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Giacomelli
authors.affiliation: CNR-ISM, Research Area Roma 1, Via Salaria km 29.300, 00015-Monterotondo Scalo (Rm), Italy.
authors.forename: M
authors.initials: M
authors.lastname: Girolami
authors.affiliation: Atominstitut, Vienna University of Technology, Vienna, Austria.
authors.forename: E
authors.initials: E
authors.lastname: Griesmayer
authors.affiliation: Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, via Roberto Cozzi 53, Milano, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Grosso
authors.affiliation: Associazione EURATOM-ENEA sulla Fusione ENEA C.R. Frascati, Via E. Fermi, 45, 00044 Frascati (Roma), Italy.
authors.forename: M
authors.initials: M
authors.lastname: Pillon
authors.affiliation: CNR-ISM, Research Area Roma 1, Via Salaria km 29.300, 00015-Monterotondo Scalo (Rm), Italy.
authors.forename: D M
authors.initials: DM
authors.lastname: Trucchi
authors.affiliation: University of Milano Bicocca, Piazza della Scienza 3, Milano, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Gorini