User`s manual

Lake Shore MTD Series Cryotest System User’s Manual
Operation 4-1
CHAPTER 4
OPERATION
4.0 GENERAL
This chapter describes the operation and shutdown of the MTD Cryotest System. Be sure to read the
entire manual before continuing. Also ensure that all instruments are working correctly prior to operating
the system. MTD System Operation is provided in Paragraph 4.1. MTD System Shutdown is provided in
Paragraph 4.2.
4.1 MTD SYSTEM OPERATION
The follow is a typical procedure for operation of the MTD Cryotest System. See the typical operational
setup in Figure 4-1.
1. To evacuate vacuum chamber, attach suitable nitrogen-trapped vacuum pumping system capable
of <20 millitorr to vacuum port. Turn on vacuum pump.
2. Fully open vacuum pumpout valve mounted on cryostat. In a clean system, 20 millitorr should be
reached in 20–30 minutes.
CAUTION: Do not pump on the MTD System when cold or contamination from the pumping
system may be “cryopumped” onto cold surfaces. Also, do not vent and back fill
system with gas during warm-up. The Model 1015 Warm-up Power Supply should
be used for rapid return to room temperature.
3. Fully close valve pumpout valve and disconnect vacuum line.
NON-MAGNETIC
KEEP
UPRIGHT
LIQUID
HELIUM
NON-
FLAMMABLE
Lake Shore
Cryotronics
Storage
Dewar
Typical
MTD-150
Transfer Line
Model 1015 Warm-Up
Power Supply
Temperature
Controller
Instrumentation Cable
Bayonet
Coupling
Cryostat
Evacuation
Valve
Pressure
Relief Valve
Vacuum Port &
Pumpout Valve
Vacuum
Pump
Flow Valve
Adjust Knob
C-MTD-4-1.eps
Figure 4-1. Typical MTD Cryotest System Operational Setup