First measurement in a magnetic confinement fusion experiment of the H3+H3→<mml:mi …

We report on the first experimental measurements made at a magnetic confinement fusion device of the tritium(T)-tritium(T) reaction <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:mtext>T</a:mtext><a:mo>+</a:mo><a:mtext>T</a:mtext><a:mo>→</a:mo><a:mrow><a:mmultiscripts><a:mi mathvariant="normal">He</a:mi><a:mprescripts/><a:none/><a:mrow><a:mn>4</a:mn></a:mrow></a:mmultiscripts><a:mo>+</a:mo><a:mn>2</a:mn><a:mi>n</a:mi></a:mrow></a:mrow></a:math> indicating the presence of the intermediate two-body resonant reaction <c:math xmlns:c="http://www.w3.org/1998/Math/MathML"><c:mrow><c:mtext>T</c:mtext><c:mo>+</c:mo><c:mtext>T</c:mtext><c:mo>→</c:mo><c:mrow><c:mmultiscripts><c:mi mathvariant="normal">He</c:mi><c:mprescripts/><c:none/><c:mrow><c:mn>5</c:mn></c:mrow></c:mmultiscripts></c:mrow><c:mo>+</c:mo><c:mi>n</c:mi></c:mrow></c:math>. During the second deuterium-tritium campaign (DTE2) at the Joint European Torus, measurements of fusion plasmas with high tritium concentrations, <e:math xmlns:e="http://www.w3.org/1998/Math/MathML"><e:mrow><e:msub><e:mi>n</e:mi><e:mtext>T</e:mtext></e:msub><e:mo>/</e:mo><e:mrow><e:mo>(</e:mo><e:msub><e:mi>n</e:mi><e:mtext>T</e:mtext></e:msub><e:mo>+</e:mo><e:msub><e:mi>n</e:mi><e:mtext>D</e:mtext></e:msub><e:mo>)</e:mo></e:mrow><e:mo>≈</e:mo><e:mn>0.99</e:mn></e:mrow></e:math>, heated with tritium neutral beam injection, were performed using the neutron time-of-flight (TOF) spectrometer TOFOR. We detect a peak in the neutron emission TOF spectrum consistent with the two-body resonant reaction. The TT neutron emission energy spectrum is modeled using an <f:math xmlns:f="http://www.w3.org/1998/Math/MathML"><f:mi>R</f:mi></f:math>-matrix framework where the distributions of the most likely model parameters given our experimental TOF data are determined utilizing a Markov chain Monte Carlo approach. We compare our best estimate of the <g:math xmlns:g="http://www.w3.org/1998/Math/MathML"><g:mrow><g:mtext>T</g:mtext><g:mo>+</g:mo><g:mtext>T</g:mtext></g:mrow></g:math> neutron emission energy spectrum with results obtained at inertial confinement fusion experiments at the OMEGA facility and find a spectral shape that is consistent with the energy dependency in the neutron spectrum observed at OMEGA. Published by the American Physical Society 2024