Study of uniform drift electric field used for boron-lined honeycomb neutron detector

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Vol. 954; p. 161431
• Main Authors: Fang, Zhujun, Yang, Yigang, Li, Yulan, Zhang, Zhi, Wang, Xuewu
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 21.02.2020
• Subjects: Drift electric field; Field uniformity; Field-cage; Field-cage; Drift electric field; Field uniformity
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/j.nima.2018.10.109

A thermal neutron detector design with a boron-lined honeycomb as the neutron converter was proposed, which can be probably a 3He alternative detector used in neutron scattering. This detector demands a high uniformity drift electric field due to the electron migration process, which simplifies the detector structure and improves the detector robustness. To research the influencing parameters to the drift electric field, the Garfield 9 and Maxwell 11 simulations were carried out. The simulation results demonstrated that both the field-cage pitch and the width of field strips determined the uniformity of drift electric field. The field-cage with optimized structure for the boron-lined honeycomb neutron detector was also designed, with 2 mm pitch, 1.5 mm width of inner field strip and 0.5 mm width of outer mirror field strip. The result of neutron experiment shows an electron migration efficiency increase of 12.4% and a neutron detection efficiency increase of 26%, demonstrating the effectiveness of field-cage optimization and drift electric field uniformity promotion. •Good electron migration requires an electric field distortion under 1%.•Small field-cage pitch and thinner field strips can suppress the electric distortion.•The summation of inner and outer field strip widths should be the same as the pitch.•The array chip resistor can simplify the field-cage structure.