Liquid-helium dewar with a two-stage pulse-tube cryocooler
MLI, vessel to shield
R
rad
=
289 K/W
q
=
0.9 W
HTS current leads
R
cond
=
1720 K/W
G10 struts, vessel to shield
R
cond
=
433 K/W
q
=
0.6 W
MLI, shield to cold mass
R
rad
=
1790 K/W
q
=
0.02 W
Instrumentation wiring
R
cond
=
239 K/W
q
=
0.15 W
G10 struts, shield to cold mass
R
cond
=
716 K/W
q
=
0.05 W
Cold mass
C
cm
=
900 J/K
HTS lead Joule heating
P
lead
=
1.2 W
Cryocooler stage 1
q
s1
=
35 W
Cryocooler stage 2
q
s2
=
1.5 W
Vacuum vessel
T
vac
=
300 K
Radiation shield
T
sh
=
40 K
Cold mass (magnet)
T
cm
=
4.2 K