High-resolution primary ion beam probe for SIMS

Quest for high brightness, monochromatic noble gas ion sources

“…8͑b͔͒ depends upon many parameters, such as the gas pressure, the magnetic field, the depth of the cell ͑L͒, the spacing between the anode A and cathode K, and the dimensions of the emission aperture. 67 Guharay et al 66 have operated Penning plasma ion source in pulsed mode and have obtained negative ion beams with a reduced brightness of 10 5 A/m 2 Sr V with an energy spread of ϳ3 eV. This brightness is about three to four orders of magnitude higher than typical values for dc beams from duoplasmatron sources.…”

“…To the best of our knowledge, the latest value of high brightness of this type of source is given by Guharay, Douglass, and Orloff. 66 In brief, the penning type plasma ion source can produce several gas ion species and with the latest achieved value of high reduced brightness, the future of this type of plasma ion source looks promising.…”

“…This brightness is about three to four orders of magnitude higher than typical values for dc beams from duoplasmatron sources. 66 The typical pulse length in pulse-mode operation can be up to 1 ms with a repetition rate up to 12 Hz. According to Guharay, Douglass, and Orloff, 66 the ion beams extracted from noiseless discharges can have a better quality.…”

“…The two types of plasma ion sources known as the Penning type [66][67][68][69][70][71][72][73][74][75] and the multicusp type [76][77][78][79][80][81][82][83][84][85][86][87] have been widely studied for focused beam applications. We will discuss these plasma ion sources and compare them with the LMIS.…”

Atomic spectrometry update. Atomic mass spectrometry

“…A new compact plasma source with Penning geometry and a discharge volume of B0.25 cm 3 delivered B1 mA of 5 keV Ar 1 , H À , O À ions through a 0.6 mm diameter exit aperture. 259 The angular beam intensity of O À beams increased linearly with the current density. Ion-optical calculations for a three-lens system predicted the feasibility of achieving sub-100 nm spots for O À beam currents of as high as 10 pA.…”