The go
al of this work w
as to design drift tubes
and
a ch
amber oper
ating in v
acuum,
and to develop technologies for tubes independent
assembly
and mounting in the ch
amber. These design
and technology were tested on the prototype. The m
ain fe
atures of the ch
amber
are the following: the drift tubes
are m
ade of flexible myl
ar film (w
all thickness 36 ¦Ìm, di
ameter 9.80 mm, length 2160 mm) using ultr
asonic welding
along the gener
atrix; the welding device
and methods were developed
at JINR. Drift tubes with end plugs,
anode wires
and sp
acers were completely
assembled outside the ch
amber. ¡°Self-centering¡± sp
acers
and bushes were used for precise setting of the
anode wires
and tubes. The
assembled tubes were se
aled with O-rings in their se
ats in the ch
amber which simplified the ch
amber
assembling. Moreover the tube
assembly
and the ch
amber m
anuf
acture c
an be performed independently
and in p
ar
allel; this sufficiently reduces the tot
al time of ch
amber m
anuf
acture
and
assembling, its cost
and
allows tubes to be tested outside the ch
amber. The technology of independent tube
assembling is suit
able for
a ch
amber of
any sh
ape but
a round ch
amber is prefer
able for oper
ation in v
acuum. Single ch
annel
amplifier-discrimin
ator bo
ards which
are more st
able
ag
ainst cross t
alks were used for testing the tubes.
Independently assembled tubes were mounted into the chamber prototype and its performance characteristic measured under the vacuum conditions. The results showed that both the structure and the tubes themselves normally operate. They are suitable for making a full-scale drift chamber for vacuum.