First neutron spectroscopy measurements with a pixelated diamond detector at JET.

A prototype Single crystal Diamond Detector (SDD) was installed at the Joint European Torus (JET) in 2013 along an oblique line of sight and demonstrated the possibility to carry out neutron spectroscopy measurements with good energy resolution and detector stability in discharges heated by neutral beam injection and radio-frequency waves. Starting from these positive results, within the Vertical Neutron Spectrometer project of the Joint European Torus, we have developed a pixelated instrument consisting of a matrix of 12 independent SDDs, called the Diamond Vertical Neutron Spectrometer (DVNS), which boosts the detection efficiency of a single SDD by an order of magnitude. In this paper we describe the main features of the DVNS, including the detector design, energy resolution, and data acquisition system for on-line processing. Preliminary spectroscopy measurements of 2.5 MeV neutrons from the present deuterium plasma at JET are finally presented.

[1]  D. M. Trucchi,et al.  The influence of grain-boundaries on the electronic performance of CVD diamond films , 2005 .

[2]  M. Nocente.  Neutron and gamma-ray emission spectroscopy as fast ion diagnostics in fusion plasmas , 2012 .

[3]  M Tardocchi,et al.  Spectral broadening of characteristic γ-ray emission peaks from 12C(3He,pγ)14N reactions in fusion plasmas. , 2011, Physical review letters.

[4]  J. Contributors,et al.  Fast-ion distributions from third harmonic ICRF heating studied with neutron emission spectroscopy , 2013 .

[5]  P. Calvani,et al.  Very Fast and Primingless Single-Crystal-Diamond X-Ray Dosimeters , 2012, IEEE Electron Device Letters.

[6]  Anders Hjalmarsson,et al.  Dual sightline measurements of MeV range deuterons with neutron and gamma-ray spectroscopy at JET , 2015 .

[7]  M. Nocente,et al.  Response function of single crystal synthetic diamond detectors to 1-4 MeV neutrons for spectroscopy of D plasmas. , 2016, The Review of scientific instruments.

[8]  G. Conte,et al.  Diamond Detectors for UV and X-Ray Source Imaging , 2012, IEEE Electron Device Letters.

[9]  G Croci,et al.  Single crystal diamond detector measurements of deuterium-deuterium and deuterium-tritium neutrons in Joint European Torus fusion plasmas. , 2014, The Review of scientific instruments.

[10]  A. Plompen,et al.  Experimental response functions of a single-crystal diamond detector for 5–20.5 MeV neutrons , 2011 .

[11]  Giuseppe Gorini,et al.  Diagnosis of physical parameters of fast particles in high power fusion plasmas with high resolution neutron and gamma-ray spectroscopy , 2013 .

[12]  G. Prestopino,et al.  Fission diamond detector tests at the ISIS spallation neutron source , 2011 .

[13]  M. Tardocchi,et al.  Time-stability of a Single-crystal Diamond Detector for fast neutron beam diagnostic under alpha and neutron irradiation , 2016 .

[14]  J. Contributors,et al.  Neutron spectroscopy measurements of tritium beam transport at JET , 2014 .

[15]  G. Gorini,et al.  Diamond detectors for fast neutron measurements at pulsed spallation sources , 2012 .

[16]  M. Tardocchi,et al.  Response of a single-crystal diamond detector to fast neutrons , 2013 .

[17]  Giuseppe Gorini,et al.  Response of LaBr3(Ce) scintillators to 14 MeV fusion neutrons , 2015 .

[18]  Anders Hjalmarsson,et al.  The 2.5-MeV neutron time-of-flight spectrometer TOFOR for experiments at JET , 2008 .

[19]  C. Verona,et al.  Single-crystal diamond detector for time-resolved measurements of a pulsed fast-neutron beam , 2010 .

[20]  M. Nocente.  Neutron emission spectroscopy measurements with a single crystal diamond detector at JET , 2016 .

[21]  J. Contributors,et al.  Fast ion energy distribution from third harmonic radio frequency heating measured with a single crystal diamond detector at the Joint European Torus. , 2015, The Review of scientific instruments.

[22]  G Croci,et al.  A diamond based neutron spectrometer for diagnostics of deuterium-tritium fusion plasmas. , 2014, The Review of scientific instruments.

[23]  C. Verona,et al.  Diamond detectors for fast neutron irradiation experiments , 2011 .

[24]  M. Marinelli,et al.  Fission diamond detectors for fast-neutron ToF spectroscopy , 2011 .