Exposure Rate In An Air-Filled Ion Chamber - Panasonic PT-DZ12000U Operating Instructions Manual

Exposure Rate in an Air-Filled Ion Chamber

X =
X =
I =
m =
% Resolution of a Gamma Spec System
% R
FWHM
peak energy = photopeak energy of interest
Resolving Time of a Gas-Filled Detector
R
C
R
0
Y
Specific Gamma-Ray Constant (Ã) for Source Activity (A)
à =
à =
ö =
E =
ã
(ì / ñ) =
en
e =
W =
Dose Rate (D) to Air from a Point Beta Source
D
A
d
I / m[1 / (2.58E-4 C / kg)-R]
exposure rate (R / sec)
current (amperes)
mass of air in chamber (kg)
= FWHM / peak energy x 100 = % resolution
= peak energy width at full width half-max height
True Count Rate Based on the
= R / (1 - R Y) = true count rate
0
= observed count rate
= resolving time
öE (ì / ñ) e / W
ã en
specific gamma constant (R-cm / hr-A)
photon fluence rate (ã / cm -hr)
gamma photon energy (MeV)
density thickness of air (g / cm )
electron charge (Coulombs)
average amount of energy to produce an ion
pair in air (eV)
2
= 300 A / d = rad /hr
= source activity in curies
= distance from source in feet
0
air
61
2
2
2