Improving thermal-neutron detection efficiency of silicon neutron detectors using the combined layers of 10B4C on 6LiF

Improving Detection Efficiency of Silicon Carbide Neutron Detector Using Double Trench

“…Also, when the neutron conversion material is 6 LiF, the following 6 Li(n, α) 3 H reaction will occur with thermal neutrons [34]: The α particles and 3 H particles produced by this reaction are also ejected in opposite directions [12], [35]. Also, the charged particles produced by the 6 Li(n, α) 3 H reaction are more powerful than those produced by the 10 B(n, α) 7 Li reaction [9]. In addition, the thermal neutron microscopic absorption cross section of the 6 Li(n, α) 3 H reaction is 940 b, and the 10 B(n, α) 7 Li reaction is 3840 b [9].…”

“…Also, the charged particles produced by the 6 Li(n, α) 3 H reaction are more powerful than those produced by the 10 B(n, α) 7 Li reaction [9]. In addition, the thermal neutron microscopic absorption cross section of the 6 Li(n, α) 3 H reaction is 940 b, and the 10 B(n, α) 7 Li reaction is 3840 b [9]. Hence, when thermal neutrons are incident on the 10 B layer and the 6 LiF layer of the same thickness, the probability of thermal neutron capture by 10 B is higher [9], [35], [36], [37].…”

“…In actual manufacturing, the front p-type ohmic contact electrode of the SiC diode was usually made of Ti with a thickness of 30 nm and Al with a thickness of 100 nm, and the backside n-type ohmic contact electrode was usually made of Ni with a thickness of 150 nm [41], [42], [43], [44], [45]. Also, the surface area of the SiC neutron detector was 1 × 1 cm 2 [9], [10], [15]. As 3 H particles with an energy of 2.73 MeV have the longest range of about 29 µm in SiC materials [3], [30], [34], [37], the thickness of SiC solid must be thick enough to ensure that charged particles can sufficiently decelerate and transfer all energy to the SiC region [9], [38], [46].…”

“…Also, the surface area of the SiC neutron detector was 1 × 1 cm 2 [9], [10], [15]. As 3 H particles with an energy of 2.73 MeV have the longest range of about 29 µm in SiC materials [3], [30], [34], [37], the thickness of SiC solid must be thick enough to ensure that charged particles can sufficiently decelerate and transfer all energy to the SiC region [9], [38], [46]. In addition, for trench-type SiC neutron detectors, the deepest trench depth we discussed is 150 µm, so 200-µm-thick SiC can guarantee that all secondary particles can be collected completely.…”

“…Thus, the output response of the semiconductor neutron detector indirectly realizes the detection of neutrons. Several groups have made substantial early contributions to the development of Si-based neutron detectors [9], [10], [11], [12], [13], [14], [15]. Typically, the thermal neutron intrinsic detection efficiency for thin-film-coated detectors is lower than 5% [6], [10], [16].…”