Low energy high angular resolution neutral atom detection by means of micro-shuttering techniques: the BepiColombo SERENA/ELENA sensor

TL;DR

The paper presents a novel low-energy neutral atom sensor, ELENA, for Mercury exploration, utilizing micro-shuttering techniques and nano-structures to achieve high angular resolution and low energy detection.

Contribution

It introduces innovative nano-structuring and micro-shuttering methods for neutral atom detection in space instruments, enhancing resolution and sensitivity.

Findings

Design techniques for neutral particle identification

Nano-structure shuttering core manufacturing

Expected count-rates for Mercury environment

Abstract

The neutral sensor ELENA (Emitted Low-Energy Neutral Atoms) for the ESA cornerstone BepiColombo mission to Mercury (in the SERENA instrument package) is a new kind of low energetic neutral atoms instrument, mostly devoted to sputtering emission from planetary surfaces, from E ~20 eV up to E~5 keV, within 1-D (2x76 deg). ELENA is a Time-of-Flight (TOF) system, based on oscillating shutter (operated at frequencies up to a 100 kHz) and mechanical gratings: the incoming neutral particles directly impinge upon the entrance with a definite timing (START) and arrive to a STOP detector after a flight path. After a brief dissertation on the achievable scientific objectives, this paper describes the instrument, with the new design techniques approached for the neutral particles identification and the nano-techniques used for designing and manufacturing the nano-structure shuttering core of the ELENA sensor. The expected count-rates, based on the Hermean environment features, are shortly presented and discussed. Such design technologies could be fruitfully exported to different applications for planetary exploration.