The Probe Device Design Of Three Window Submarine In-situ X-ray Fluorescence Detection System

The paper research is derived from "The development of submarine in situ X ray fluorescence detection system" which is one of the projects of China Geological Survey’s ocean mineral resources security projects.This paper aimed at design the structure of undersea probe device which is the key component of submarine in-situ X-ray fluorescence detection system. Analyze and estimate the mechanical function of probes in the bottom of the sea water environment, considering the pressure, abrasion resistance and water dynamics of probe on the bottom of the sea to design the mechanical structure of the probe; Selected the appropriate shell materials and detection window materials, design of eccentric weights increase device, to realize of provide reliable mechanical excitation and detection device for seafloor sediments in sea water environment elements.In this paper the main research results are as follows:(1) According to the structural composition of sea bottom in situ X fluorescence detection system, the geometric dimension of sea bottom probe device inside sensor circuit unit and arouse detection device to select the shell material is2A12aluminum alloy, the probe structural design for cylinder. And all the other related dimensions have been designed and calculated;(2) Considering the X-ray tube with a small power are selected as excitation source for undersea detection apparatus, in order to make the original level of X-ray and characteristic X-ray can be "free" in the bottom of the sea probe device, designed three window structure underwater sensor detection window which with beryllium as the window material, tests have shown that beryllium window can satisfy the requirement of X-ray is free to probe; (3) In order to avoid the submarine probe cannot be effectively contact the seabed sediments caused by traction from vessel, design add eccentric weights increase tail and eccentric heavier front-end on probe device, to ensure that at least one detection window of the seabed probe can keep close contact with seabed sediment in the process of drag;(4) Designed the underwater sealing structure of probe, which can ensure the bottom of the sea probe device no leakage under the condition of in1000m water depth in sea.Probe device design have been fabricated by certain geological instrument factory. Through a series of tests and experiments at the bottom of lake and sea, show that the design of probe device of X-ray fluorescence detection system is feasible, can let the three window submarine in-situ X-ray fluorescence detection system complete the in situ measurement under the setting work condition. All the experimental measuring results and the results come from samples on the vessel are consistent, also proved the accuracy of the in-situ measuring system.