11:30 〜 11:45
[PCG17-12] Material analyzer based on diamagnetic and paramagnetic separation
キーワード：磁気分離、非破壊分析、物質同定
A method has been proposed to conduct material analysis in a remote onsite-mission to investigate mixture of heterogeneous particles immediately after collecting them [1]. The method was based on a field- induced translation that was observed in various diamagnetic solids in a static field that monotonically decreased along one direction (i.e., along an x-axis) [2]; here the particles wwere released at a common position x0 in a microgravity area with negligibly small initial velocity. In order to obtain diamagnetic susceptibility χDIA per unit mass of the particle, a formula was deduced from an energy conservation between initial position x0 and an arbitrary position xi of the particle as
vi2 =χDIA (Bi2 - B02). (1)
In the above equation, velocity of particle at position xi was described as vi, while B0 and Bi denote field intensities at positions x0 and xi, respectively. It is seen that mass m of particle is deleted in the equation, and χDIA is obtained from the linear correlation between vi2 and Bi2 - B02 obtained for many xi ’s without the necessity of measuring m. Furthermore, material of the particle is estimated by collating χDIA with a list of published values without consuming the small sample.
In the present report, efficiency of eq. (1) is examined for major materials that compose the interstellar solid particles, namely corundum, diamond, graphite, magnesia and silicon-carbide. The accuracy in observing vi and Bi were considerably improved by introducing a new high-speed camera (CASIO EX-F1, Japan), The experimental χDIA values of the aforementioned materials were consistent with the published values. These values range from χDIA = −52×10-7 emu/g to χDIA = −2.8×10-7 emu/g, which overlap with the published values compiled for existing materials. Hence and the observed translation may commonly occur in most solids according to the laws of energy conservation as described in eq.(1). The deviation and experimental and published values are less than 1 × 10-7 emu/g, which shows that present system is capable of estimating the material of a particle from the χDIA values. This is because the variance of published χDIA between different materials are usually larger than 1×10-7 emu/g for typical inorganic materials.
The abovementioned method of material analyses fulfil the following qualities required for an apparatus adopted in an on-site mission; (1) principle of analysis should be simple and well confirmed. (2) apparatus should be compact and rigid, (3) power consumption must be low. (4) Rare and precious particles must be preserved for a sample return. The resolution of material identification the setup developed in the present study was high enough to be used as a prototype to develop an apparatus solid particle in an on-site mission.
For further application, degree of unsaturation assigned to an organic crystal was estimated from the swift χDIA measurement. The improved Pascal rule concludes that the magnitude of χDIA generally show a positive correlation with the extent of unsaturation assigned to an organic molecule, and diamagnetic magnetization caused by a π-bond is an order of magnitude larger than the magnetization caused by a σ-bond (see Table I). For example, the absolute χDIA value of graphite exceeds the value of diamond by a factor of ten owing to the excess of π-bonds. Note that the two materials are carbon allotropes. In the resource exploration of coal and/or petroleum, the degree of unsaturation has been conventionally used as an indicator to evaluate the maturity of a sample. It has been used as a major parameter for estimating the extent of biological evolution of carbonaceous materials extracted from various natural samples. In conclusion, the proposed method is suitable for conducting preliminary analysis of a solid particle shortly after they are collected in a remote exploration, prior to many stages of refined analysis.
[1] K. Hisayoshi et al., Sci. Rep 6 (2016). [2]C. Uyeda et al. Sci. Rep 6 (2019) .
vi2 =χDIA (Bi2 - B02). (1)
In the above equation, velocity of particle at position xi was described as vi, while B0 and Bi denote field intensities at positions x0 and xi, respectively. It is seen that mass m of particle is deleted in the equation, and χDIA is obtained from the linear correlation between vi2 and Bi2 - B02 obtained for many xi ’s without the necessity of measuring m. Furthermore, material of the particle is estimated by collating χDIA with a list of published values without consuming the small sample.
In the present report, efficiency of eq. (1) is examined for major materials that compose the interstellar solid particles, namely corundum, diamond, graphite, magnesia and silicon-carbide. The accuracy in observing vi and Bi were considerably improved by introducing a new high-speed camera (CASIO EX-F1, Japan), The experimental χDIA values of the aforementioned materials were consistent with the published values. These values range from χDIA = −52×10-7 emu/g to χDIA = −2.8×10-7 emu/g, which overlap with the published values compiled for existing materials. Hence and the observed translation may commonly occur in most solids according to the laws of energy conservation as described in eq.(1). The deviation and experimental and published values are less than 1 × 10-7 emu/g, which shows that present system is capable of estimating the material of a particle from the χDIA values. This is because the variance of published χDIA between different materials are usually larger than 1×10-7 emu/g for typical inorganic materials.
The abovementioned method of material analyses fulfil the following qualities required for an apparatus adopted in an on-site mission; (1) principle of analysis should be simple and well confirmed. (2) apparatus should be compact and rigid, (3) power consumption must be low. (4) Rare and precious particles must be preserved for a sample return. The resolution of material identification the setup developed in the present study was high enough to be used as a prototype to develop an apparatus solid particle in an on-site mission.
For further application, degree of unsaturation assigned to an organic crystal was estimated from the swift χDIA measurement. The improved Pascal rule concludes that the magnitude of χDIA generally show a positive correlation with the extent of unsaturation assigned to an organic molecule, and diamagnetic magnetization caused by a π-bond is an order of magnitude larger than the magnetization caused by a σ-bond (see Table I). For example, the absolute χDIA value of graphite exceeds the value of diamond by a factor of ten owing to the excess of π-bonds. Note that the two materials are carbon allotropes. In the resource exploration of coal and/or petroleum, the degree of unsaturation has been conventionally used as an indicator to evaluate the maturity of a sample. It has been used as a major parameter for estimating the extent of biological evolution of carbonaceous materials extracted from various natural samples. In conclusion, the proposed method is suitable for conducting preliminary analysis of a solid particle shortly after they are collected in a remote exploration, prior to many stages of refined analysis.
[1] K. Hisayoshi et al., Sci. Rep 6 (2016). [2]C. Uyeda et al. Sci. Rep 6 (2019) .