Calculation of the profile-dependent neutron backscatter matrix for the JET neutron camera system

• We investigated the dependence of the backscatter component of the neutron spectrum on the emissivity profile. We did so for the JET neutron camera system, by calculating a profile-dependent backscatter matrix for each of the 19 camera channels using a MCNP model of the JET tokamak. We found that, when using a low minimum energy for the summation of the counts in the neutron pulse height spectrum, the backscatter contribution can depend significantly on the emissivity profile. The maximum variation in the backscatter level was 24% (8.0% when compared to the total emission). This effect needs to be considered when a correction for the backscatter contribution is applied to the measured profile.

Subject headings

Natural Sciences  (hsv)

Physical Sciences  (hsv)

Subatomic Physics  (hsv)

Naturvetenskap  (hsv)

Fysik  (hsv)

Subatomär fysik  (hsv)

Keyword

Neutron

Profile monitor

Backscatter

mcnp