4.2. Liquid Ionization Chamber 229
whereμionrepresents the mobility of ions. Fig.4.1.8 shows an experimental curve
of drift velocity of ions in liquid argon versus applied electric field intensity. It is
apparent that the above equation holds up to a good approximation. The mobility
in this case will be almost constant, which can be seen in Fig.4.1.9.
Figure 4.1.8: Variation of drift
velocity of ions in liquid argon
with respect to applied electric
field. The parameters F and
G are related to the experiment
and are irrelevant for our discus-
sion (15).Figure 4.1.9: Variation of mo-
bility of ions in liquid argon
with respect to applied electric
field. The parameters F and
G are related to the experiment
and are irrelevant for our discus-
sion (15).4.2 LiquidIonizationChamber
Amongst the liquid filled detectors, the ionization chambers are the most widely
used. Most of these detectors are filled with liquid noble gases such as liquid argon
but other liquids are also now being investigated and used. Liquid filled ionization
chambers have some very favorable characteristics that make it suitable for use in a
variety of applications, some of which are listed below.
Stability:Ionization chambers are stable over a longer period of time as com-
pared to, for example liquid proportional counters. The main reason for this
is their less vulnerability to small degradation of the liquid with time.