Charge resolved electrostatic diagnostic of colliding copper laser plasma plumes

Journal Article · Sat Oct 15 04:00:00 EDT 2011 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3633486· OSTI ID:22046975

Yeates, P ^[1]; Fallon, C ^[2]; Kennedy, E T; Costello, J T ^[1]

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1. National Centre for Plasma Science and Technology (NCPST), Dublin City University (DCU) (Ireland)
2. School of Physical Sciences, Dublin City University (DCU), Dublin (Ireland)

The collision of two laser generated plasma plumes can result, under appropriate conditions, in the formation of a ''stagnation layer.'' The processes underlying this phenomenon are complex and time dependent. The majority of experiments over the last few decades have focused upon spectroscopic diagnostic of colliding plasmas. We have performed electrostatic diagnosis of multiply charged copper ions (Cu{sup +} to Cu{sup 5+}) generated via Q-switched pulsed laser ({lambda} = 1.06 {mu}m, {tau} = 6 ns, and E{sub L} = 52-525 mJ) generation of copper plasma plumes from a planar target. Time dependent current traces, charge yields, and kinetic energy (K{sub e}) distributions are obtained for single plasma plumes (S{sub p}) and colliding plasma plumes (C{sub p}). The charge yield from a C{sub p} relative to twice that from a S{sub p} is characterized by a charge yield ratio (CYR) parameter. Superior ion yields for all charge states occur for a discrete range of fluences (F) from colliding plasma plumes leading to a CYR parameter exceeding unity. The kinetic energy distributions from colliding plasma plumes display well defined energy compression via narrowing of the distributions for all fluences and charge states. The extent of this energy compression is charge dependent. Space charge forces within the stagnation layer and the resulting charge dependent acceleration of ions are proposed to account for the transfer of ion kinetic energy in favour of collisional ionization mechanisms.

• OSTI ID: 22046975
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 10 Vol. 18; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CHARGE STATES
COLLISIONS
COMPRESSION
COPPER
COPPER IONS
IONIZATION
KINETIC ENERGY
LASER-PRODUCED PLASMA
MULTICHARGED IONS
PLASMA DIAGNOSTICS
PLASMA GUNS
PLASMA PRODUCTION
PLUMES
SPACE CHARGE
TIME DEPENDENCE