Beta Dose Rates - Panasonic PT-DZ12000U Operating Instructions Manual

Beta Dose Rates in rad/hr per mCi
MeV 1 cm
0.15 1,200
0.25 1,000
0.30 900
0.50 750
0.75 650
1.0 550
1.25 450
1.50 400
1.75 350
2.00 340
2.25 320
Beta dose should be treated as a "shallow" dose and should
not be summed with "deep" doses. This chart should also be
used to determine beta+ doses from positron emitters.
Half-value Thickness vs Beta Energy
Isotope
C-14
Tc-99
Cl-36
Sr/Y-90
U-238 Betas from short lived progeny
P-32
Estimate the half-value thickness for a beta emitter.
2
mg/cm = 50 x E
where E is Emax in MeV for the beta emitter
This equation tends to underestimate the half-value
thickness for low energy betas and overestimate the
half-value thickness for high energy betas.
10 cm 30 cm
1.7 0
2.2 0.1
3.6 0.1
5.2 0.4
5.0 0.5
4.6 0.4
4.3 0.4
4.0 0.4
3.4 0.4
3.6 0.4
3.3 0.4
Emax (MeV)
0.156
0.292
0.714
0.546 / 2.284
0.191 / 2.281
1.710
2
60 cm
0
0
0
0.05
0.05
0.1
0.1
0.1
0.1
0.1
0.1
Half-Value Thickness mg / cm
90 cm 1.0 m
0 0
0 0
0 0
0.01 0
0.01 0
0 0
0.04 0.02
0.04 0.02
0.04 0.02
0.04 0.02
0.04 0.02
2
7.5
15
150
130
150
2