Penning ion source

The cross section for the 3H(maximum value at only 107 KeV incident deuteron energy. When thick ( 1 mg cm-2 thick deposit of titanium) titanium-tritium targets are used, however, the neutron yield continues to increase even above 200 KV acceleration potential. This is due to increased penetration of the deuteron beam into the tritium enriched layer. Since the penetration of molecular deuterium ions is less than that for monatomic deuterium ions for the same acceleration potential, accelerators using Penning ion sources require extremely clean vacuum systems to minimize build-up of deuteron absorbing deposits on the surface of the target. 

Fig. 14. Schematic diagram of a penning ion source with radial ion extraction...

Penning ion source for various applications. Lorrain has pointed out that there is a similarity of this type of ion source with that devised earlier by Maxwell Also, as Dushman and Lafferty point out, the inverted magnetron due to Redhead has efficient electron trapping in the discharge region and is related to the Penning ion source. 

The specific Penning ion sources employed in the study of the doubly-charged negative ions have been described In a typical experiment involving a... 

Figure 16 presents the mass spectrum obtained with iodine in the Penning ion source and no electric deflection employed. The peak observed at M/z = 63.5 may be due to and/or to the daughter ion of a metastable transition occurring prior to the magnetic sector. 

Since the formation of a wide variety of doubly-charged negative monatomic ionic species is possible with a Penning ion source, and since nA beam currents of the T species may be obtained after momentum/charge and kinetic energy analysis with magnetic and electric sectors, photodetachment studies of the species... 

There are many more types of cluster ion sources than there are neutral cluster sources, in part because of the wide variety of ion-forming techniques available and in part because cluster ion sources are often hybrids of established neutral cluster sources and ion-forming environments. Some non-hybrid ion sources which can generate cluster ions include ion sputter, flow tube. Penning... 

Penning ionization occurs with the (trace) gas M having an ionization energy lower than the energy of the metastable state of the excited (noble gas) atoms A. The above ionization processes have also been employed to construct mass spectrometer ion sources. [21,24] However, Penning ionization sources never escaped the realm of academic research to find widespread analytical application. 

Glow discharge ion source in Ar plasma Penning and e ionization plasma 3000-6000 ne 1015 cm-3 M+ low pressure double-focusing SFMS (reverse Nier-Johnson) traces, high-purity metals... 

The above mechanisms for the formation of and S are plausible and explain the observation of 0 and S by Stuckey and Kiser and by Baumann, Heinicke, Kaiser and Bethge. They specifically involve excited states both of Z and of Z. And the lifetime of the Z would permit significant concentrations of Z to be formed in a plasma source, such as found in the omegatron or the Penning source. However, it is anticipated that only much lower concentrations of Z would be formed in the Nier-type ion source employed in most conventional mass spectrometers. It is unlikely, therefore, that the above mechanisms can satisfactorily account for the observation of F formed from CF3CI, as reported by Ahnell and Koski or the various Z species reported by Bowie and Stapleton ... 

A total ion monitor (TIM), though not part of the interface, is often useful for the GC MS operation. The TIM is an ion detector positioned in the analyzer tube between the ion source and the magnet and is adjustable to collect a certain percentage of the total ions formed. This detector response is registered on a dual pen strip chart recorder with that of the GG flame detector (Figure 6). There may be some difiFerences in peak ratios because of differences in detector responses to the various compounds the mass spectra are taken at the TIM peak maxima since the ions are then most concentrated. Pesticide residue analysis by GG MS... 

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