In-situ measurement of Ejecta using Flash X-ray

Paper number

IAC-09.A6.P.13

Author

Mr. Hiroshi Takakura, Kyushu Institute of Technology, Japan

Coauthor

Dr. Yasuhiro Akahoshi, Kyushu Institute of Technology, Japan

Coauthor

Ms. Masumi Higashide, Tokai University, Japan

Coauthor

Mr. Takao Koura, Kyushu Institute of Technology, Japan

Coauthor

Mr. Tomohiro Narumi, Kyushu University, Japan

Year

2009

Abstract

The impact of space debris with a space structure such as the International Space Station is considered to be questionable with an increase of space debris in recent years due to space development. The modeling of debris environment is performed as an example of a measure. The impact with debris is avoided using the debris environmental model. But, the error has produced the debris environmental model between the U.S. and Europe. The range of the portion which an error produces notably is 1cm from 100 $\mu$μm. The debris environmental model of the range of the above-mentioned size is the most unreliable. It is a size important for the debris-proof design of a space machine. About 100 $\mu$μm debris causes to the surface damage to a space machine. Moreover, debris with a size of about 1mm may penetrate a space machine. The source of the above-mentioned size is considered to be ejecta. The debris of the cause is observed for it by measurement of JAXA. It is a fine fragment called the secondary debris generated when it impacts with a space structure. It is thought that there are few examples of a fixed quantity examination of it, and it has caused the error between models. Therefore, it is thought that it is pressing need to increase the example of an examination of fixed quantity evaluation of it. Then, the purposes of this research are to measured and the size, number of particles and velocity at the time of ejecta generating, and to evaluate the ratio of ejecta total mass to projectile mass, and the size distribution of the fragments. In order to generate ejecta, in this research, it experimented by using the two-stage light gas gun of a space environment technical center. Capture of ejecta used the witness plate. A witness plate is used to collect ejecta particles released from the front side of the target during impact. The size and number of ejecta were measured by the capture material. After measuring, it classified in the following ranges.
\begin{itemize}\item $<$0.010 mm (mainly from the ejecta cone);
\end{itemize} 
\begin{itemize}\item Between 0.01 and 0.1 mm (mainly from the ejecta cone);\end{itemize}
\begin{itemize}\item Between 0.1 and 1 mm (mainly from spall);\end{itemize}
\begin{itemize}\item $>$1mm (from spall).
\end{itemize}
Velocity was computed by take the picture at the time of ejecta generating using Flush X-ray.

Abstract document

IAC-09.A6.P.13.pdf

Manuscript document

IAC-09.A6.P.13.pdf (🔒 authorized access only).

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