<s>
The	O
construction	O
of	O
the	O
LExan	O
Bubble	B-Algorithm
Chamber	I-Algorithm
,	O
LEBC	B-Algorithm
,	O
was	O
approved	O
by	O
the	O
CERN	O
Research	O
Board	O
on	O
16	O
November	O
1978	O
.	O
</s>
<s>
Bubble	B-Algorithm
chambers	I-Algorithm
are	O
similar	O
to	O
cloud	O
chambers	O
,	O
both	O
in	O
application	O
and	O
in	O
basic	O
principle	O
.	O
</s>
<s>
As	O
particles	O
enter	O
the	O
chamber	O
,	O
a	O
piston	B-Device
suddenly	O
decreases	O
its	O
pressure	O
,	O
and	O
the	O
liquid	O
enters	O
into	O
a	O
superheated	O
,	O
metastable	O
phase	O
.	O
</s>
<s>
LEBC	B-Algorithm
was	O
20	O
centimetres	O
in	O
diameter	O
and	O
contained	O
one	O
litre	O
of	O
liquid	O
hydrogen	O
.	O
</s>
<s>
It	O
was	O
designed	O
to	O
look	O
for	O
charmed	O
particles	O
,	O
a	O
type	O
of	O
particles	O
that	O
are	O
so	O
unstable	O
that	O
they	O
usually	O
decay	O
too	O
quickly	O
to	O
be	O
detected	O
in	O
big	O
bubble	B-Algorithm
chambers	I-Algorithm
.	O
</s>
<s>
The	O
bubbles	O
in	O
a	O
small	O
chamber	O
like	O
LEBC	B-Algorithm
were	O
about	O
ten	O
times	O
smaller	O
compared	O
to	O
the	O
bubbles	O
in	O
the	O
large	O
chambers	O
.	O
</s>
<s>
Hence	O
,	O
LEBC	B-Algorithm
had	O
a	O
higher	O
probability	O
of	O
detecting	O
short	O
tracks	O
.	O
</s>
<s>
LEBC	B-Algorithm
was	O
used	O
for	O
several	O
CERN	O
experiments	O
in	O
Geneva	O
,	O
among	O
others	O
NA13	O
,	O
NA16	O
and	O
NA27	O
,	O
before	O
it	O
was	O
transported	O
to	O
Fermilab	O
outside	O
Chicago	O
where	O
it	O
was	O
used	O
for	O
experiment	O
E743	O
.	O
</s>
<s>
The	O
NA13	O
experiment	O
was	O
performed	O
by	O
exposing	O
LEBC	B-Algorithm
without	O
any	O
down-stream	O
particle	O
spectrometer	O
.	O
</s>
<s>
While	O
for	O
the	O
NA16	O
experiment	O
,	O
LEBC	B-Algorithm
was	O
placed	O
at	O
the	O
vertex	O
position	O
of	O
the	O
European	O
Hybrid	O
Spectrometer	O
(	O
EHS	O
)	O
that	O
provided	O
momentum	O
analysis	O
,	O
particle	O
identification	O
and	O
gamma	O
detection	O
for	O
secondaries	O
emerging	O
from	O
the	O
hydrogen	O
interactions	O
.	O
</s>
