scholarly journals Two-dimensional ion emission from laser-produced plasmas

1983 ◽  
Vol 1 (2) ◽  
pp. 171-180 ◽  
Author(s):  
G. J. Tallents
Keyword(s):  
Plasma Temperature ◽  
Relative Number ◽  
Two Dimensions ◽  
Energy Spectra ◽  
Ion Probe ◽  
Initial Plasma ◽  
Cold Component ◽  
Ion Kinetic Energy ◽  
Cold Ions ◽  
Ion Emission

The expansion of laser-produced plasmas in two-dimensions is examined analytically using an asymptotic (time→∞) isothermal self-similar model. The ion emission velocity and energy spectra are calculated and expressions given for the number and energy of expanding ions as a function of angle to the target. By relating the total ion kinetic energy of expansion to the temperature of the initial plasma, it is shown that ion probe signals give a measure of the initial plasma temperature. The model is extended to a plasma with two initial temperatures (a ‘hot’ component and a ‘cold’ component) and it is shown that the ion energy spectra here can be used to deduce the initial temperatures of the ‘hot’ and ‘cold’ ions and the relative number of the ‘hot’ ions to the ‘cold’ ions. The results are used to interpret data from an array of ion probes (at different angles to the target) for a plasma produced by irradiating a 25 μm thick nickel foil with a ∼20 ρs neodymium laser pulse.

scholarly journals Linear dependence of surface expansion speed on initial plasma temperature in warm dense matter

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
W. Bang ◽  
B. J. Albright ◽  
P. A. Bradley ◽  
E. L. Vold ◽  
J. C. Boettger ◽  
...  
Keyword(s):  
Linear Dependence ◽  
Plasma Temperature ◽  
Dense Matter ◽  
Warm Dense Matter ◽  
Initial Plasma ◽  
Expansion Speed ◽  
Surface Expansion

scholarly journals One Dimensional Shock Refraction at a Plasma-cold Gas Interface

1973 ◽  
Vol 28 (10) ◽  
pp. 1668-1675
Author(s):  
J. Gerofi ◽  
H. K. Messerle
Keyword(s):  
Plasma Temperature ◽  
Region Of Interest ◽  
Initial Pressure ◽  
Step Function ◽  
Initial Plasma ◽  
Function Discontinuity ◽  
Definition Of ◽  
Shock Refraction ◽  
Weak Shocks ◽  
Cold Gas

Refraction and reflection of a shockwave at a plasma/cold gas interface has been studied using an R.F. preheated section in an electrothermal shock tube. The gas used in the experiment was Argon at initial pressures from 10 to 30 Torr, with initial temperature of 9000 K.A detailed numerical analysis of the refraction event has been undertaken using a method that does not require definition of an effective γ. Methods that do use such a γ are not accurate, except for very weak shocks. Because of short ionization times it has been possible to assume equilibrium behind the various shock waves. Calculations suggest that in the region of interest, reflected and refracted shock velocities depend primarily on initial shock velocity, slightly on initial plasma temperature and very weakly on initial pressure. The analysis covers initial temperatures of 6000 to 12 000 K and initial pressures of 10 to 50 Torr.Calculations and experimental results are presented. These show that a step function discontinuity is a good approximation to the nature of the plasma cold gas interface in this situation.

Rearrangements in the Molecular Ions of Some ortho-Substituted Schiff Bases

1993 ◽  
Vol 46 (6) ◽  
pp. 895 ◽  
Author(s):  
T Blumenthal ◽  
M Dosen ◽  
RG Gillis ◽  
QN Porter
Keyword(s):  
Kinetic Energy ◽  
Schiff Bases ◽  
Molecular Ions ◽  
Energy Spectra ◽  
Supporting Evidence ◽  
Deuterium Labelling ◽  
Methyl Group ◽  
Molecular Ion ◽  
Fragment Ions ◽  
Ion Kinetic Energy

Under electron ionization conditions, the ortho-substituted Schiff bases N-benzylidene-o-toluidine (1a), N-(o-methylbenzylidene)aniline (1b), N-salicylideneaniline (1c) and N-(o-methoxybenzylidene)aniline (1d) give fragment ions which have been shown by collision-activated mass-analysed ion kinetic energy spectra to have the structure of the protonated molecular ions of indole (2), benzofuran (3), and 1,2-benzisoxazole (4). The molecular ion of N-(o-methylbenzylidene)-o-toluidine (1f) gives as fragment ions not only the protonated molecular ion (2) of indole and the tropylium ion but also the molecular ion of anthracene. Attempts to find supporting evidence for a mechanism for this rearrangement by deuterium labelling of a methyl group in (1b), such as (1g), have been unsuccessful.

Angle-dependence of ion kinetic energy spectra obtained by using mass spectrometers II. Experimental considerations and preliminary results on non-fragmenting systems

1984 ◽  
Vol 392 (1802) ◽  
pp. 89-106 ◽  
Keyword(s):  
Kinetic Energy ◽  
Energy Analysis ◽  
Energy Spectra ◽  
Observation Angle ◽  
Initial Angle ◽  
Mass Spectrometers ◽  
Small Uncertainty ◽  
Ion Kinetic Energy ◽  
Double Focusing ◽  
Selection Of

Experimental problems associated with studies of the scattering of kilovolt projectile ions in mass spectrometers designed primarily for chemical analysis are discussed. The parameters that are important in satisfactorily controlling and defining the actual scattering angle in relation to the observation angle are considered in detail. Two different experimental configurations are considered; angular selection before, or after kinetic energy analysis of the collision products. A modification to a VG ZAB-2F double-focusing mass spectrometer, in order to observe angle-resolved ion kinetic energy spectra of collisionally scattered ion beams, is described. Initial angle-resolved experiments on systems that do not involve fragmentation, have been performed. The results are presented for the angle-resolved energy loss spectra of Ar + and N 2 + and the angle-resolved charge-stripping of Ar + . A feature of the apparatus described is the small uncertainty in the angular selection of the analysing angle-resolved slit.

Sign in / Sign up

Export Citation Format

Share Document