Lakeshore 642, User Manual

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Lake Shore Model 642 Electromagnet Power Supply User’s Manual
B-2 Units for Magnetic Properties
Table B-2. Recommended SI Values for Physical Constants
Quantity Symbol Value (SI units)
Permeability of Vacuum
µ
0
4
π
× 10
-7
H m
-1
Speed of Light in Vacuum c 2.9979 × 10
8
m s
-1
Permitivity of Vacuum
ε
0
= (µ
0
c
2
)
-1
8.8542 × 10
-12
F m
-1
Fine Structure Constant, µ0ce2/2h
α
α -1
0.0073
137.0360
Elementary Charge e 1.6022 × 10
-19
C
Plank's Constant
h
h = h/2
π
6.6262 × 10
-34
J Hz
-1
1.0546 × 10
-34
J s
Avogadro's Constant N
A
6.0220 × 10
23
mol
-1
Atomic Mass Unit 1 u = 10
-3
kg mol
-1
/N
A
1.6605 × 10
-27
kg
Electron Rest Mass m
e
0.9109 × 10
-30
kg
5.4858 × 10
-4
u
Proton Rest Mass m
p
1.6726 × 10
-27
kg
1.0073 u
Neutron Rest Mass m
n
1.6749 × 10
-27
kg
1.0087 u
Magnetic Flux Quantum
φ
= h/2e
h/e
2.0679 × 10
-15
Wb
4.1357 × 10
-15
J Hz
-1
C
-1
Josephson Frequency-Voltage Ratio 2e/h 483.5939 THz V
-1
Quantum of Circulation
h/2m
e
h/m
e
3.6369 × 10
-4
J Hz
-1
kg
-1
7.2739 × 10
-4
J Hz
-1
C
-1
Rydberg Constant
R
∞
1.0974 × 10
7
m
-1
Proton Moment in Nuclear Magnetons
µ
p
/µ
N
2.7928
Bohr Magneton µ
B
= eh/2m
e
9.2741 × 10
-24
J T
-1
Proton Gyromagnetic Ratio γ
p
2.6752 × 10
8
s
-1
T
-1
Diamagnetic Shielding Factor, Spherical H
2
O Sample
1 +
σ
(H
2
O)
1.0000
Molar Mass Constant R 8.3144 J mol
-1
K
-1
Molar Volume, Ideal Gas (T
0
= 273.15K, p
0
= 1 atm) V
m
= RT
0
/p
0
0,0224 m
3
mol
-1
Boltzman Constant k = R/N
A
1.3807 × 10
-23
J K
-1
Stefan-Boltzman Constant σ
= (
π
2
/60) k
4
/h
3
c
2
5.6703 × 10
-8
W m
-2
K
-4
First Radiation Constant
c
1
= 2
π
hc
2
3.7418 × 10
-16
W m
-2
Second Radiation Constant c
2
= hc/k 0.0144 mK
Gravitation Constant G 6.6720 × 10
-11
N m
2
kg
-2
Data (abbreviated to 4 decimal places) from CODATA Bulletin No. 11, ICSU CODATA Central Office, 19 Westendstrasse,
6 Frankfurt/Main, Germany. Copies of this bulletin are available from this office.