Interplay of cavitation bubble and plasma emision during single pulse laser induced breakdown on submerged target
Узајамно дејство кавитационог мехура и зрачења плазме код пробоја индукованог једним ласерским импулсом на мети у течности
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Although the experimental setup needed for the plasma and cavitation bubble
creation with the laser is relatively simple, enormous variety of physical processes
take place in this experiment, covering the topics from
uid dynamics, to heat
and mass transfer, to chemical reactions, plasma physics and light emission. Laser
induced plasma (LIP) shows a wide range of characteristics depending on the experimental
parameters used for its creation. In addition to the complexity of the
LIP itself, when such a plasma is created inside the liquid environment several extra
factors come into play, making both the experimental and theoretical investigation
highly challenging tasks. In a liquid environment, besides plasma formation due
to the laser action, the shock wave and cavitation bubble are created, all of them
sharing the input laser energy. Due to the interrelation of the phenomena occurring
after laser induced breakdown (LIB) in liquid environment, shock wave, bubble and
plasma emission, in... order to get real insight into the physics of the processes, one
need to study more than one eect at the same time.
In this study main focus was on the last two aspects of the LIB, i.e. cavitation
bubble and plasma emission, while the subject of the shock wave emergence and
propagation was also discussed in short. The mutual impact of these two extremely
interesting phenomena, laser produced plasma and the cavitation bubble, is considered
very important for numerous applications, the production of nanoparticles
being one of the more popular recently. Cavitation bubble plays a crucial role in
determining the size, shape and chemistry of the products of laser ablation in liquid.
Although its importance have been recognized and many research groups are dealing
with this topic, a lots of speculations about the role of the cavitation bubble in
nanoparticles production still exist. Another point on which the opinions about the
cavitation bubble are divergent regards the question of double pulse laser induced
breakdown spectroscopy (DP-LIBS). Plasma-bubble relations in DP-LIBS are still
not very well documented, while the relation between the plasma and bubble in single
pulse laser induced breakdown spectroscopy (SP-LIBS) are almost completely missing...
Eksperimentalna postavka potrebna za stvarae plazme i mehura u vodi rel-
ativno je jednostavna, ali je raznovrsnost fiziqkih procesa koji se odigravaju
u ovom eksperimentu ogromna, obuhvatajui po a od dinamike fluida, prenosa
toplote i mase, hemijskih reakcija, fizike plazme i emisije svetlosti. Laser-
ski proizvedena plazma LPP moe imati xirok spektar karakteristika u zav-
isnosti od korixenih ekpserimentalnih parametara. Pored sloenosti same
LPP, kada se takva plazma formira unutar teqnosti, nekoliko dodatnih fak-
tora postaje relevantno, xto qini i teorijska i eksperimentalna istraivaa
izazovnim zadatkom. U teqnom okrueu, pored formiraa plazme dolazi i do
formiraa udarnog talasa i kavitacionog mehura od kojih svaki proces troxi
deo energije. Usled meusobne povezanosti ovih pojava, kako bi se dobio pravi
uvid u fiziku procesa, potrebno je prouqavati vixe procesa istovremeno.
U ovom radu glavni akcenat istraivaa je na kavitacionom mehuru i zraqeu
plazme, dok je pitae pojav ivaa udarno...g talasa i egovog prostiraa disku-
tovano u kratkim crtama. Uzajamno dejstvo ova dva veoma interesantna fenom-
ena, laserski proizvedene plazme i kavitacionog mehura, veoma je vano za
veliki broj primena, od kojih je u poslede vreme proizvoda nanoqestica
najpopularnija. Kavitacioni mehur ima presudnu ulogu u odreivau veli-
qine, oblika i hemije proizvoda laserske ablacije u teqnosti. Iako je vanost
mehura prepoznata i mnoge istraivaqke grupe se bave ovom tematikom i da e
postoji dosta nejasnoa oko uloge kavitacionog mehura u proizvodi nanoqes-
tica. Druga tema oko koje takoe postoje neslagaa oko kavitacionog mehura
je spektroskopija laserski indukovanog proboja sa dva laserska impulsa. (DP
LIBS). Odnosi izmeu plazme i mehura u DP LIBS-u jox uvek nisu dovo no
dokumentovani, dok je takav odnos kod laserskog proboja jednim impulsom (SP
LIBS) apsolutna nepoznanica...