The n_TOF NEAR Station Commissioning and first physics case

Abstract

The NEAR Station is a new experimental area developed at the n_TOF Facility at CERN. The activation station of NEAR underwent a characterization of the beam following the installation of the new n_TOF Spallation Target. The commissioning of the neutron beam comprises a set of simulations made with the FLUKA code and experimental verification. The experimental determination of the neutron spectrum was made using activation techniques with three separate set-ups. Two set-ups were based on the Multi-foil Activation technique (MAM-1 and MAM-2), and the third set-up relied on the process of neutron moderation and activation of a single material (ANTILoPE). The three set-ups are presented. Also the present plans and future perspectives of the activation station of NEAR are discussed.

The n_TOF facility at CERN

“…The NEAR station has two sub-stations [4], the irradiation station (i-NEAR), located next to the target and the activation station (a-NEAR) located outside the shielding, approximately at 3 meters from the target. The NEAR experimental area was commissioned in 2021 [5], with the aim of studying the effect of radiation on material and electronics, as well as performing cross-section measurements with the activation technique. An example of an activation spectrum is given in Figure 3 [5].…”

“…The NEAR experimental area was commissioned in 2021 [5], with the aim of studying the effect of radiation on material and electronics, as well as performing cross-section measurements with the activation technique. An example of an activation spectrum is given in Figure 3 [5].…”

“…The choice of detector depends on the specific experiment and the type of measurement being made. In particular, for the measurements of capture reactions, a high-performance 4p Total Absorption Calorimeter (TAC), made of 42 BaF2 crystals has been built (Figure 4) and extensively used, while innovative gas detectors, such as Fast Ion Chamber (FIC) [5], Parallel plate avalanche chambers (PPACs, Figure 4), and fission detectors, such as MICRO-Mesh-Gaseous Structure (Micromegas) [6,7,8], have been developed for measurements of fission cross-sections.…”

“…One of those developments is the imaging-Total Energy Detector (i-TED) setup [9], see Figure 5 right panel. i-TED is a γ-ray A background spectrum is also shown (in red) [5]. detection system based on the Compton imaging technique.…”

“…3 Activation spectrum, in counts per second, for the Au-6 ( 197 Au(n,2n) 196 Au) foil (in black). A background spectrum is also shown (in red)[5].…”