The High Energy Neutron Detector HEND was developed in the Laboratory of space gamma ray spectroscopy of the Space Research Institute (Moscow, Russia). It was constructed under contract with Russian Aviation Space Agensy (Rosaviakosmos) in accordance with the Federal Program of Basic Space Exploration of Russia. Joint Institute for Nuclear Researches (Dubna, Russia) participated in development of the physical concept of HEND.

Installation of HEND on the spacecraft "2001 Mars Odyssey" has been performed in accordance with Implementation Agreement between Rosaviakosmos and NASA. 

The joint Russian-United States science team created for HEND's data processing and results analysis.  

The main parameters of HEND are presented in Table 1.

   

General view  

General view of Flight Unit # 2 of HEND on technological supports from the sight direction between axis +X and +Y (the scale of ruler is cm). To see view the device from the sight direction between axis -X and –Y move "mouse" on picture

Detector HEND view

Construction

To see more about design of  HEND's detector LD, MD, SD and scintillation block SC, click on the squares  in the picture. To see more about electronics click on the detector.

Main parameters of HENDMain parameters of HENDSD detectorMD DetectorBlock of ScintilatorsLD DetectorSchema of HEND

Detectors

HEND (see Figures) integrates in one instrument a set of five particles sensors and the electronics boards.  The set of sensors includes 3 proportional counters (LD, MD, SD) and scintillation block (SC) with 2 scintillators. Proportional counters and internal scintillator have different sensitivities for neutrons with different energies. When all these sensors are switched on, HEND allows to measure neutrons at broad energy range from 0.4 eV up to 10.0 MeV. 

Sensors SD, MD, LD and internal scintillator SC/IN have different sensitivities for neutrons with different energies, and when they used jointly allow measuring the energy spectrum of neutrons from 0.4 eV up to 10.0 MeV. Scintillation sensor SC/IN measure fast neutrons by detection of recoil protons resulted from their inelastic scattering atoms of hydrogen. The special electronics circuit designed for this sensor to distinguish between counts from recoil protons and counts from gamma rays. The reduction efficiency of this circuit is higher than 1000.