Impact Ionisation Mass Spectrometry of Cosmic Dust Analogues I: Active Asteroids and Hydrated Minerals

3200号小行星法厄同是一颗“活跃”的小行星，它的光谱和动力学特征与小行星相似，表面没有挥发物的迹象，但其尘埃排放却像彗星一样，产生了双子座流星流。法厄同上的水合和/或羟基化矿物的热干燥和开裂被认为是尘埃排放的驱动力。然而，这些矿物的成分和数量在法厄同的尘埃中还没有被确定，在一般的行星际和星际尘埃中也仍然没有得到很好的限制。斯拉马湾斯图加特），搭载即将到来的日本命运+航天器，代表了一个独特的机会，通过阳离子和阴离子碰撞电离质谱测量这些尘埃的组成。该项目将产生金属涂层，富含水的矿物学宇宙尘埃类似物，并将其静电加速到实验室碰撞电离质谱仪，包括DDA飞行备用/实验室模型。这些颗粒产生的质谱，以及非水合/-羟基化对照样品，将被表征以预测天然存在的含水颗粒的预期质谱，提供用于其定量鉴定的校准因子，并进一步理解撞击速度和颗粒质量对所产生的谱的作用。

Asteroid 3200 Phaethon is an "active" asteroid, one which spectroscopically and dynamically resembles an asteroid, with no sign of surface volatiles, and yet which exhibits comet-like dust emission, generating the Geminid meteor stream.Thermal desiccation and cracking of hydrated and/or hydroxylated minerals on Phaethon has been postulated as a driver for the dust emission. However, the composition and quantity of these minerals has not been identified in dust from Phaethon and also remains poorly constrained in the general interplanetary and interstellar dust populations.The Destiny Dust Analyser (DDA) instrument (PI R. Srama, U. Stuttgart), onboard the upcoming Japanese Destiny+ spacecraft, represents a unique opportunity to measure the composition of these dusts via cation and anion impact ionisation mass spectrometry.This project will produce metal-coated, water-rich mineralogical cosmic dust analogues and electrostatically accelerate them onto laboratory impact ionisation mass spectrometers, including the DDA flight spare/laboratory models.The mass spectra produced by these grains, as well as by non-hydrated/-hydroxylated control samples, will be characterised in order to predict the mass spectra expected from naturally-occurring water-containing grains, provide calibration factors for their quantitative identification and further understand the role of impact velocity and particle mass on the generated spectra.