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贝塞尔盒型能量分析仪由三部分组成 :一个圆筒形电极、一个中心圆盘和两个带中心孔的侧板 ,该分析仪结构简单、结实 ,十分适用于电离规和四极质谱计上。对电离规而言 ,分析仪被放置于电离器及离子收集器之间。在栅型电离器中所产生的离子被分离并注入到能量分析仪中。分析仪依据其激发的能量把电离器中产生的气相离子和栅网表面上脱附的电子激励解吸的离子分离开。如果应用一个法拉第杯型离子收集器和一个灵敏的直流放大器来进行离子流测量的话 ,那么该电离规测量范围在 10 - 1 0 ～ 10 - 3Pa之间。当二次电子倍增器采用脉冲计数方法时 ,所测量的压力范围在 10 - 1 1～ 10 - 6 Pa之间 (Ax TRAN,ISX2 ,U L VAC公司 ) .其典型灵敏度对氮气而言为 (6 .7± 0 .2 )× 10 - 3Pa- 1 和对氢而言为 (2 .3± 0 .0 4 )× 10 - 3Pa- 1 。对四极质谱计而言 ,能量分析仪被置于在电离器和四极滤质器之间。装有该分析仪的质谱计 ,给出了没有电子激励解吸离子的简单质谱。该分析仪能使四极质谱计的离子收集器免受从栅网表面发射的 X射线的辐射 ,和从电离器中的离子以及被激发的分子在退激励过程中释放的紫外线的辐射。这种屏蔽作用改善了在 10 - 3Pa范围内的气体中微量杂质的检测极限 ,使之降至亿分之几
Bessel Box Energy Analyzer consists of three parts: a cylindrical electrode, a central disk and two side plates with a central hole, the analyzer is simple, strong, very suitable for ionization and quadrupole mass spectrometry Counting. For ionization gauges, the analyzer is placed between the ionizer and the ion collector. The ions generated in the grid type ionizer are separated and injected into the energy analyzer. The analyzer separates the gas phase ions generated in the ionizer from the electron-excited desorbed ions desorbed on the surface of the grid in response to their excited energy. If a Faraday cup ion trap and a sensitive DC amplifier are used for ion flow measurement, the gauge measures between 10 - 10 and 10 - 3 Pa. The measured pressure range is between 10 - 1 1 and 10 - 6 Pa (Axtran, ISX2, UL VAC) when using a pulse counting method with a secondary electron multiplier. The typical sensitivity for nitrogen is (6 .7 ± 0 .2) × 10 -3 Pa -1 and (2.3 ± 0. 0 4) × 10 -3 Pa -1 for hydrogen. For quadrupole mass spectrometers, the energy analyzer is placed between the ionizer and quadrupole mass filter. A mass spectrometer equipped with this analyzer gives a simple mass spectrum without electronically excited desorption ions. This analyzer protects the ion trap of the quadrupole mass spectrometer from the radiation of X-rays emitted from the grid surface and from the ions in the ionizer and the UV light emitted by the excited molecules during the de-excitation process. This shielding effect improves the detection limit of trace impurities in the gas in the range of 10 - 3 Pa to a few hundred millionths