Ionization probability of sputtered coronene molecules

2019 ◽  
Vol 460 ◽  
pp. 193-200
Author(s):  
M. Herder ◽  
J. Klein ◽  
A. Sevim ◽  
A. Wucher
Keyword(s):  
Ionization Probability

Field-assisted ionization theory for microscopists

1994 ◽  
Vol 52 ◽  
pp. 820-821
Author(s):  
Patrick P. Camus
Keyword(s):  
Electric Field ◽  
Electron Tunneling ◽  
Ionization Probability ◽  
Critical Distance ◽  
Tunneling Probability ◽  
Field Ionization ◽  
Radius Of Curvature ◽  
Field Evaporation ◽  
A Value ◽  
Ion Emission

The theory of field ion emission is the study of electron tunneling probability enhanced by the application of a high electric field. At subnanometer distances and kilovolt potentials, the probability of tunneling of electrons increases markedly. Field ionization of gas atoms produce atomic resolution images of the surface of the specimen, while field evaporation of surface atoms sections the specimen. Details of emission theory may be found in monographs.Field ionization (FI) is the phenomena whereby an electric field assists in the ionization of gas atoms via tunneling. The tunneling probability is a maximum at a critical distance above the surface,xc, Fig. 1. Energy is required to ionize the gas atom at xc, I, but at a value reduced by the appliedelectric field, xcFe, while energy is recovered by placing the electron in the specimen, φ. The highest ionization probability occurs for those regions on the specimen that have the highest local electric field. Those atoms which protrude from the average surfacehave the smallest radius of curvature, the highest field and therefore produce the highest ionizationprobability and brightest spots on the imaging screen, Fig. 2. This technique is called field ion microscopy (FIM).

Wirkungsquerschnitte der Photoabsorption und Photoionisation des N2-Moleküls

1969 ◽  
Vol 24 (12) ◽  
pp. 1941-1952
Author(s):  
F.J. Comes ◽  
K.W. Weber
Keyword(s):  
High Resolution ◽  
Cross Sections ◽  
Ionization Probability ◽  
Nitrogen Molecule ◽  
Strong Variation ◽  
Radiationless Transitions ◽  
Continuous Absorption ◽  
The Cross

AbstractThe cross sections of photoabsorption and photoionization of the nitrogen molecule have been determined with high resolution (Δλ: 0.08 Å). The experiments demonstrate that the continuous absorption is overlapped by strong bands which are diffuse due to radiationless transitions. The competition of autoionization and predissociation leads to a strong variation of the ionization probability. Arguments are given to explain this behaviour of the nitrogen bands.

Untersuchungen zur Wirkung von monochromatischer Vakuum-UV-Strahlung auf DNS

1969 ◽  
Vol 24 (6) ◽  
pp. 722-728 ◽  
Author(s):  
K. U. Berger
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Electron Emission ◽  
Vacuum Ultraviolet ◽  
Monochromatic Light ◽  
Ionization Probability ◽  
Thin Layers ◽  
Inactivation Mechanism ◽  
Grating Monochromator ◽  
Vacuum Uv

Inactivation cross sections of infectious ΦΧ-174-DNA in the extreme vacuum-ultraviolet were determined by irradiation of thin layers with monochromatic light down to 584 Å by means of a powerful grating-monochromator, the elements of which are described. Comparison of inactivation and light-induced electron emission shows that light of quantum energies below 7 eV inactivates by excitation only, whereas above 10.2 eV ionization is the predominant inactivation mechanism. Because of the satisfactory agreement of the curves for inactivation and electron emission, it is conducted that the remarkable increase of the inactivation cross section in the region of the short wavelength vacuum-uv is due to increasing ionization probability.

scholarly journals The Effect of Magnetic Field Strength and Geometry on the Deposition Rate and Ionized Flux Fraction in the HiPIMS Discharge

Plasma ◽  
2019 ◽  
Vol 2 (2) ◽  
pp. 201-221 ◽  
Author(s):  
Hamidreza Hajihoseini ◽  
Martin Čada ◽  
Zdenek Hubička ◽  
Selen Ünaldi ◽  
Michael A. Raadu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Deposition Rate ◽  
Average Power ◽  
Current Mode ◽  
Ionization Probability ◽  
Cathode Voltage ◽  
Peak Current ◽  
Voltage Mode ◽  
Operating Modes ◽  
The Magnetic Field

We explored the effect of magnetic field strength | B | and geometry (degree of balancing) on the deposition rate and ionized flux fraction F flux in dc magnetron sputtering (dcMS) and high power impulse magnetron sputtering (HiPIMS) when depositing titanium. The HiPIMS discharge was run in two different operating modes. The first one we refer to as “fixed voltage mode” where the cathode voltage was kept fixed at 625 V while the pulse repetition frequency was varied to achieve the desired time average power (300 W). The second mode we refer to as “fixed peak current mode” and was carried out by adjusting the cathode voltage to maintain a fixed peak discharge current and by varying the frequency to achieve the same average power. Our results show that the dcMS deposition rate was weakly sensitive to variations in the magnetic field while the deposition rate during HiPIMS operated in fixed voltage mode changed from 30% to 90% of the dcMS deposition rate as | B | decreased. In contrast, when operating the HiPIMS discharge in fixed peak current mode, the deposition rate increased only slightly with decreasing | B | . In fixed voltage mode, for weaker | B | , the higher was the deposition rate, the lower was the F flux . In the fixed peak current mode, both deposition rate and F flux increased with decreasing | B | . Deposition rate uniformity measurements illustrated that the dcMS deposition uniformity was rather insensitive to changes in | B | while both HiPIMS operating modes were highly sensitive. The HiPIMS deposition rate uniformity could be 10% lower or up to 10% higher than the dcMS deposition rate uniformity depending on | B | and in particular the magnetic field topology. We related the measured quantities, the deposition rate and ionized flux fraction, to the ionization probability α t and the back attraction probability of the sputtered species β t . We showed that the fraction of the ions of the sputtered material that escape back attraction increased by 30% when | B | was reduced during operation in fixed peak current mode while the ionization probability of the sputtered species increased with increasing | B | , due to increased discharge current, when operating in fixed voltage mode.

Ionization probability of sputtered atoms

1983 ◽  
Vol 27 (4) ◽  
pp. 2019-2029 ◽  
Author(s):  
N. D. Lang
Keyword(s):  
Ionization Probability

On the SIMS Ionization Probability of Organic Molecules

2017 ◽  
Vol 28 (6) ◽  
pp. 1182-1191 ◽  
Author(s):  
Nicholas J. Popczun ◽  
Lars Breuer ◽  
Andreas Wucher ◽  
Nicholas Winograd
Keyword(s):  
Organic Molecules ◽  
Ionization Probability

Measurements of the Ionization Probability of CU and LaB^{6} Simulated Micrometeors

1971 ◽  
Vol 166 ◽  
pp. 717 ◽  
Author(s):  
J. F. Friichtenicht ◽  
D. G. Becker
Keyword(s):  
Ionization Probability
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