M. Gilchriese

Thermal Shock

M. Gilchriese2

Thermal Shock - Sector 9• Use liquid nitrogen vapor to cool sector rapidly.• Setup is just dewar, valve and line to sector. Open valve, look

at temperature, close valve when cold enough.• Next step would be to implement simple temperature

controller.• Plot below is without power on sector.

Sector LN2 Cooled T vs time

-50

-40

-30

-20

-10

0

10

20

30

0 10 20 30 40 50

Time(sec)

T(C

)

M. Gilchriese3

Sector 9• Sector has been tested with C3F8, irradiated to 11 Mrads, raised to +135C, and now cooled

with LN2 to about -35C without power, operated near -35C with power, then cooled to about -60C.

• Imaging done in usual way with room T water at about 21C. • Before in the pictures that follow means before thermal shock but after all other tests.• There is no evidence for any significant change in thermal performance after thermal shock

tests.• In addition, it appears possible to easily cool sector with LN2 to actual operating

temperature, assuming can implement simple temperature feedback/controller.

M. Gilchriese4

Before

After thermal shock to -35C

Power on operation at about -35 to -25C. LN2 enters left.

After thermal shock to -60C