A novel energy analyzer with a simple structured Bessel box has been successfully developed and incorporated into ionization gauges and quadrupole mass spectrometers (QMS) to improve their measurement of the total and...A novel energy analyzer with a simple structured Bessel box has been successfully developed and incorporated into ionization gauges and quadrupole mass spectrometers (QMS) to improve their measurement of the total and partial pressures,respectively.We found that the energy analyzer may not only effectively separate the gas phase ions and electron stimulated desorption (ESD) ions produced in the ionizer,but also screen the ion collector from irradiation of the soft X rays and VUVphotons generated in the ionizer.The screening effects considerably better the trace impurity detection limit of the QMS down to a few tens ppb in the pressure range of 10 -3 Pa.The modified ionization gauge is capable of measuring pressure ranging from 10 -11 to 10 -6 Pa in the pulse counting mode and its upper limit may extends to 10 -3 Pa in DC ion current mode with typical sensitivities factor of(6.7±0.2)×10 -3 Pa -1 for N 2 and (2.3±0.2)×10 -3 Pa -1 for H 2,respectively.No ESD ions was observed in the simple looking spectrum obtained with the modified QMS.We also found that the energy spectra of fragment ions depend strongly on species of parent ions.展开更多
Quadrupole mass spectrometer (QMS) is an instrument for effectively determining gaseous composition of fluid inclusion. The gaseous component is extracted from inclusions with thermal decrepitation method and then det...Quadrupole mass spectrometer (QMS) is an instrument for effectively determining gaseous composition of fluid inclusion. The gaseous component is extracted from inclusions with thermal decrepitation method and then determined with the sensitive QMS instrument. The method is characterized by high sensitivity and high accuracy with the relative standard deviation (RSD,n=6) of less than 3%. It has been successfully used for analyzing fluid inclusions. The analytical results meet the requirement of geological study.展开更多
文摘A novel energy analyzer with a simple structured Bessel box has been successfully developed and incorporated into ionization gauges and quadrupole mass spectrometers (QMS) to improve their measurement of the total and partial pressures,respectively.We found that the energy analyzer may not only effectively separate the gas phase ions and electron stimulated desorption (ESD) ions produced in the ionizer,but also screen the ion collector from irradiation of the soft X rays and VUVphotons generated in the ionizer.The screening effects considerably better the trace impurity detection limit of the QMS down to a few tens ppb in the pressure range of 10 -3 Pa.The modified ionization gauge is capable of measuring pressure ranging from 10 -11 to 10 -6 Pa in the pulse counting mode and its upper limit may extends to 10 -3 Pa in DC ion current mode with typical sensitivities factor of(6.7±0.2)×10 -3 Pa -1 for N 2 and (2.3±0.2)×10 -3 Pa -1 for H 2,respectively.No ESD ions was observed in the simple looking spectrum obtained with the modified QMS.We also found that the energy spectra of fragment ions depend strongly on species of parent ions.
基金This work was supported by Academia Sinica Resource and Environment Project (Grant No.KZ951-B1-404). The experiment and analysis were carried out in the Institute of Geology and Geophysics, Chinese Academy of Sciences. The authors appreciate Prof. Kuro
文摘Quadrupole mass spectrometer (QMS) is an instrument for effectively determining gaseous composition of fluid inclusion. The gaseous component is extracted from inclusions with thermal decrepitation method and then determined with the sensitive QMS instrument. The method is characterized by high sensitivity and high accuracy with the relative standard deviation (RSD,n=6) of less than 3%. It has been successfully used for analyzing fluid inclusions. The analytical results meet the requirement of geological study.
