APPROXIMATE NEUTRON ENERGIES
cold neutrons
0 - 0.025 eV
thermal 0.025
eV
epithermal
0.025 - 0.4 eV
cadmium
0.4 - 0.6 eV
epicadmium
0.6 - 1 eV
slow
1 eV - 10 eV
resonance
10 eV - 300 eV
intermediate
300 eV - 1 MeV
fast
1 MeV - 20 MeV
relativistic
> 20 MeV
Note: A thermal neutron is one which has the same energy and
moves at the same velocity as a gas molecule does at a
temperature of 20 degrees C. The velocity of a thermal neutron
is 2200 m / sec (~5,000 mph).
Neutron Fluence per mrem (10CFR20)
n/cm
n/cm /s
n/cm
n/cm /s
2
2
2
2
per
per
per
per
MeV
mrem
mrem/hr
MeV
mrem
mrem/hr
thermal .......
......
10
2.4E4
6.7
to
9E5
250
14
1.7E4
4.7
1E-2
........
.......
20
1.6E4
4.4
1E-1
1.7E5
47
40
1.4E4
6.7
5E-1
3.9E4
11
60
1.6E4
4.4
1
2.7E4
7.5
100
2E4
5.6
2.5
2.9E4
8
200
1.9E4
5.3
5
2.3E4
6.4
300
1.6E4
4.4
7
2.4E4
6.7
400
1.4E4
6.7
1
66
APPROXIMATE NEUTRON ENERGIES
cold neutrons
0 - 0.025 eV
thermal 0.025
eV
epithermal
0.025 - 0.4 eV
cadmium
0.4 - 0.6 eV
epicadmium
0.6 - 1 eV
slow
1 eV - 10 eV
resonance
10 eV - 300 eV
intermediate
300 eV - 1 MeV
fast
1 MeV - 20 MeV
relativistic
> 20 MeV
Note: A thermal neutron is one which has the same energy and
moves at the same velocity as a gas molecule does at a
temperature of 20 degrees C. The velocity of a thermal neutron
is 2200 m / sec (~5,000 mph).
Neutron Fluence per mrem (10CFR20)
n/cm
n/cm /s
n/cm
n/cm /s
2
2
2
2
per
per
per
per
MeV
mrem
mrem/hr
MeV
mrem
mrem/hr
thermal .......
......
10
2.4E4
6.7
to
9E5
250
14
1.7E4
4.7
1E-2
........
.......
20
1.6E4
4.4
1E-1
1.7E5
47
40
1.4E4
6.7
5E-1
3.9E4
11
60
1.6E4
4.4
1
2.7E4
7.5
100
2E4
5.6
2.5
2.9E4
8
200
1.9E4
5.3
5
2.3E4
6.4
300
1.6E4
4.4
7
2.4E4
6.7
400
1.4E4
6.7
1
66
APPROXIMATE NEUTRON ENERGIES
cold neutrons
0 - 0.025 eV
thermal 0.025
eV
epithermal
0.025 - 0.4 eV
cadmium
0.4 - 0.6 eV
epicadmium
0.6 - 1 eV
slow
1 eV - 10 eV
resonance
10 eV - 300 eV
intermediate
300 eV - 1 MeV
fast
1 MeV - 20 MeV
relativistic
> 20 MeV
Note: A thermal neutron is one which has the same energy and
moves at the same velocity as a gas molecule does at a
temperature of 20 degrees C. The velocity of a thermal neutron
is 2200 m / sec (~5,000 mph).
Neutron Fluence per mrem (10CFR20)
n/cm
n/cm /s
n/cm
n/cm /s
2
2
2
2
per
per
per
per
MeV
mrem
mrem/hr
MeV
mrem
mrem/hr
thermal .......
......
10
2.4E4
6.7
to
9E5
250
14
1.7E4
4.7
1E-2
........
.......
20
1.6E4
4.4
1E-1
1.7E5
47
40
1.4E4
6.7
5E-1
3.9E4
11
60
1.6E4
4.4
1
2.7E4
7.5
100
2E4
5.6
2.5
2.9E4
8
200
1.9E4
5.3
5
2.3E4
6.4
300
1.6E4
4.4
7
2.4E4
6.7
400
1.4E4
6.7
1
66
APPROXIMATE NEUTRON ENERGIES
cold neutrons
0 - 0.025 eV
thermal 0.025
eV
epithermal
0.025 - 0.4 eV
cadmium
0.4 - 0.6 eV
epicadmium
0.6 - 1 eV
slow
1 eV - 10 eV
resonance
10 eV - 300 eV
intermediate
300 eV - 1 MeV
fast
1 MeV - 20 MeV
relativistic
> 20 MeV
Note: A thermal neutron is one which has the same energy and
moves at the same velocity as a gas molecule does at a
temperature of 20 degrees C. The velocity of a thermal neutron
is 2200 m / sec (~5,000 mph).
Neutron Fluence per mrem (10CFR20)
n/cm
n/cm /s
n/cm
n/cm /s
2
2
2
2
per
per
per
per
MeV
mrem
mrem/hr
MeV
mrem
mrem/hr
thermal .......
......
10
2.4E4
6.7
to
9E5
250
14
1.7E4
4.7
1E-2
........
.......
20
1.6E4
4.4
1E-1
1.7E5
47
40
1.4E4
6.7
5E-1
3.9E4
11
60
1.6E4
4.4
1
2.7E4
7.5
100
2E4
5.6
2.5
2.9E4
8
200
1.9E4
5.3
5
2.3E4
6.4
300
1.6E4
4.4
7
2.4E4
6.7
400
1.4E4
6.7
1
66