|Budget Amount *help
¥12,100,000 (Direct Cost: ¥12,100,000)
Fiscal Year 1994: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1993: ¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 1992: ¥8,600,000 (Direct Cost: ¥8,600,000)
A new toroidal gas insulated plasma (GIP) source was designed and (a) quartz, (b) metallic discharge tubes were constructed. Using the gas vortex flow as plasma support gas, it was able to sustain the stable toroidal Ar plasma on the center of discharge tube up to 760 Torr in each discharge tube.
The new GIP source doesn't need preparatory ionization and doesn't have any electrode, so maintenance caused by consumption of electrode isn't needed. Therefore, extremely long time operation is possible. Because the vortex flow of plasma support gas induced that plasma can't touch the discharge tube, so high purity plasma is obtained.
From these characteristics, we are thinking that this GIP source is useful for fields that have problems of impurities in the plasma, for example excitation medium of laser, diamond film preparation, etc.
Furthermore it is consider that this plasma source can be applied to large emission area UV source for industrial use. To generate higher temperature plasma for d
ecomposition of industrial wastes, for example PCB,enlargement of vessel and power up are needed using metallic discharge tube.
Argon inductively coupled plasma mass spectrometry (Ar ICP-MS) is a multielement technique with excellent detection limits and the added ability to provide isotopic information.To overcome some problems of the Ar ICP,new torch for helium ICP is developed. By the flow visualization using spark tracing method, it is founded that with the conventional torch for Ar ICP,adequate helium gas vortex flow to sustain the stable plasma doesn't form in the plasma generate region. Spatial measurement of helium emission intensity is performed, and generation of doughnut plasma is confirmed. Therefore, we designed and developed new enhanced vortex flow torch for He ICP and stable helium plasma was generated by that torch.
Furthermore, He ICP mass spectrometry (He ICP-MS) device that will have high sensitivity for high ionization energy elements was developed using that torch. Effects of sampler-skimmer distance on the pressure in the 2nd stage and on the ion signal intensities were studied and it was found that both the Mach disk position and the most suitable position for analysis are 7 mm. No background spectral peak was found at m/z values over 32 except for copper from the sampler.
Ion intensities of neon and krypton that were low in sensitivity in argon ICP-MS due to their high ionization energies were as much as 36 and 24 times greater in He ICP-MS,respectively. Less