<s>
The	O
MicroMegas	B-Algorithm
detector	I-Algorithm
(	O
Micro-Mesh	O
Gaseous	O
Structure	O
)	O
is	O
a	O
gaseous	O
particle	B-Algorithm
detector	I-Algorithm
coming	O
from	O
the	O
development	O
of	O
the	O
wire	O
chamber	O
.	O
</s>
<s>
Invented	O
in	O
1992	O
by	O
Georges	O
Charpak	O
and	O
Ioannis	O
Giomataris	O
,	O
the	O
Micromegas	B-Algorithm
detectors	I-Algorithm
are	O
mainly	O
used	O
in	O
experimental	O
physics	O
,	O
in	O
particular	O
in	O
particle	O
physics	O
,	O
nuclear	O
physics	O
and	O
astrophysics	O
for	O
the	O
detection	O
of	O
ionising	O
particles	O
.	O
</s>
<s>
The	O
Micromegas	B-Algorithm
are	O
light	O
detectors	O
in	O
order	O
to	O
minimize	O
the	O
perturbation	O
on	O
the	O
impinging	O
particle	O
.	O
</s>
<s>
They	O
are	O
a	O
type	O
of	O
micropattern	B-Algorithm
gaseous	I-Algorithm
detector	I-Algorithm
with	O
a	O
spatial	O
resolution	O
below	O
one	O
hundred	O
micrometers	O
.	O
</s>
<s>
Nowadays	O
,	O
the	O
use	O
of	O
the	O
Micromegas	B-Algorithm
technology	O
is	O
growing	O
throughout	O
the	O
different	O
fields	O
of	O
experimental	O
physics	O
.	O
</s>
<s>
A	O
particle	B-Algorithm
detector	I-Algorithm
is	O
used	O
to	O
detect	O
a	O
passing	O
particle	O
and	O
obtain	O
information	O
such	O
as	O
its	O
position	O
,	O
arrival	O
time	O
and	O
momentum	B-Algorithm
.	O
</s>
<s>
The	O
Micromegas	B-Algorithm
detector	I-Algorithm
detects	O
particles	O
by	O
amplifying	O
the	O
charges	O
that	O
have	O
been	O
created	O
by	O
ionisation	O
in	O
the	O
gas	O
volume	O
.	O
</s>
<s>
In	O
a	O
Micromegas	B-Algorithm
detector	I-Algorithm
,	O
this	O
gas	O
volume	O
is	O
divided	O
in	O
two	O
by	O
a	O
metallic	O
micro-mesh	O
(	O
“	O
Micromesh	O
”	O
on	O
the	O
schematic	O
)	O
placed	O
between	O
25	O
μm	O
and	O
150	O
μm	O
of	O
the	O
readout	O
electrode	O
(	O
Strips	O
on	O
the	O
schematic	O
)	O
.	O
</s>
<s>
Accelerated	O
by	O
this	O
field	O
,	O
the	O
electron	O
acquires	O
enough	O
energy	B-Algorithm
to	O
produce	O
ion/electron	O
pairs	O
that	O
will	O
also	O
ionise	O
the	O
gas	O
,	O
creating	O
pairs	O
;	O
this	O
is	O
the	O
avalanche	O
effect	O
(	O
4	O
)	O
.	O
</s>
<s>
The	O
amplitude	O
and	O
the	O
shape	O
of	O
the	O
signal	O
,	O
read	O
via	O
the	O
electronic	O
on	O
the	O
readout	O
electrode	O
,	O
gives	O
information	O
on	O
the	O
time	O
and	O
energy	B-Algorithm
of	O
the	O
particle	O
.	O
</s>
<s>
The	O
ionic	O
signal	O
carries	O
more	O
than	O
half	O
of	O
the	O
signal	O
and	O
is	O
used	O
to	O
reconstruct	O
the	O
energy	B-Algorithm
of	O
the	O
particle	O
.	O
</s>
<s>
In	O
1991	O
,	O
to	O
improve	O
the	O
detection	O
of	O
hadrons	O
at	O
the	O
Hadron	O
Blind	O
Detector	O
experiment	O
,	O
I	O
.	O
Giomataris	O
and	O
G	O
.	O
Charpak	O
reduced	O
the	O
amplification	O
gap	O
of	O
a	O
parallel	O
plate	O
detector	O
(	O
a	O
type	O
of	O
spark	B-Algorithm
chamber	I-Algorithm
)	O
in	O
order	O
to	O
speed	O
up	O
the	O
signal	O
.	O
</s>
<s>
Nevertheless	O
,	O
the	O
benefits	O
of	O
a	O
reduce	O
amplification	O
gap	O
had	O
been	O
demonstrated	O
and	O
the	O
micro-mesh	O
gaseous	O
structure	O
or	O
Micromegas	B-Algorithm
concept	O
was	O
born	O
in	O
October	O
1992	O
,	O
shortly	O
before	O
the	O
announcement	O
of	O
the	O
Nobel	O
prize	O
attribution	O
to	O
Georges	O
Charpak	O
for	O
the	O
invention	O
of	O
the	O
wire	O
chambers	O
.	O
</s>
<s>
Starting	O
in	O
1992	O
at	O
CEA	O
Saclay	O
and	O
CERN	O
,	O
the	O
Micromegas	B-Algorithm
technology	O
has	O
been	O
developed	O
to	O
provide	O
more	O
stable	O
,	O
reliable	O
,	O
precise	O
and	O
faster	O
detectors	O
.	O
</s>
<s>
In	O
2001	O
,	O
twelve	O
large	O
Micromegas	B-Algorithm
detectors	I-Algorithm
of	O
40	O
x	O
40cm2	O
were	O
used	O
for	O
the	O
first	O
time	O
in	O
a	O
large	O
scale	O
experiment	O
at	O
COMPASS	O
situated	O
on	O
the	O
Super	O
Proton	O
Synchrotron	O
accelerator	O
at	O
CERN	O
.	O
</s>
<s>
Another	O
example	O
of	O
the	O
development	O
of	O
the	O
Micromegas	B-Algorithm
detectors	I-Algorithm
is	O
the	O
invention	O
of	O
the	O
“	O
bulk	O
”	O
technology	O
.	O
</s>
<s>
For	O
instance	O
,	O
by	O
modifying	O
the	O
micro-mesh	O
in	O
order	O
to	O
make	O
it	O
photo-sensitive	O
to	O
UV	B-Application
light	O
,	O
the	O
Micromegas	B-Algorithm
can	O
be	O
used	O
to	O
detect	O
forest	O
fires	O
.	O
</s>
<s>
A	O
photo-sensitive	O
Micromegas	B-Algorithm
is	O
also	O
used	O
for	O
fast-timing	O
applications	O
.	O
</s>
<s>
The	O
PICOSEC-Micromegas	O
uses	O
a	O
Cherenkov	O
radiator	O
and	O
a	O
photocathode	O
in	O
front	O
of	O
the	O
gaseous	O
volume	O
and	O
a	O
time	O
resolution	O
of	O
24	O
ps	O
is	O
measured	O
with	O
minimum	O
ionizing	O
particles	O
(	O
MIP	O
)	O
.	O
</s>
<s>
The	O
Micromegas	B-Algorithm
detectors	I-Algorithm
are	O
now	O
used	O
in	O
several	O
experiments	O
:	O
</s>
<s>
Micromegas	B-Algorithm
detector	I-Algorithm
will	O
be	O
used	O
in	O
the	O
ATLAS	O
experiment	O
,	O
as	O
part	O
of	O
their	O
upgrade	O
of	O
its	O
future	O
muon	O
spectrometer	O
.	O
</s>
