User`s manual

Lake Shore MTD Series Cryotest System User’s Manual

Introduction 1-9

P-MTD-1-07.bmp

Figure 1-7. Typical Square Fanout Board (Top View)

FIRST STAGE HEAT EXCHANGER: Located on the cryostat cold finger. This stage provides cooling to

the radiation shield and signal lead heat sinks. A DT-470 series silicon diode temperature sensor

and 2 cartridge heaters are mounted to this stage for temperature monitoring, temperature control

and rapid warm-up.

FLOW VALVE: Controls flow of cryogen through the transfer line.

INSTRUMENTATION FEEDTHRU CONNECTOR: The 19-pin Instrumentation Feedthru Connector is

located on the underside of the dewar. Temperature control and measurement electrical

connections are made through the O-ring sealed electrical feedthru. Only 8 of the 19 pins are used

in a standard Model MTD-150 Installation. This allows for future installation of additional

instrumentation leads. See Figure 1-8 for connector definition.

INTERFACE BOARD: Provides electrical interface between signal lines and fanout board. Contains

spring loaded, gold plated beryllium copper fingers which contact the 50 Ω stripline transmission

lines on the fanout board.

MAIN CHAMBER: Main section of vacuum chamber, mounted to vacuum chamber base plate. May be

removed for access to system wiring and mechanical components.

MICROCOAX CABLING SIGNAL LINES: 100 semi-rigid stainless steel microcoax cables which

interconnect the interface board and the four 25-line feedthru connectors. The 100 cables are

thermally sunk with epoxy to the radiation shield base plate to reduce heat conduction along the

lines to the cold plate. The maximum current on any one signal line is 100 mA. If additional current

is required, use copper leads and the spare pins on the Instrumentation Feedthru Connector.

RADIATION SHIELD: Gold plated radiation shield which controls the radiation environment around the

DUT. When removed, provides access to the test set assembly.

SECOND STAGE HEAT EXCHANGER: Located on the cold finger end. Contains a DT-470 series

silicon diode temperature sensor and 2 cartridge heaters. Provides cooling and temperature control

for the DUT and accessories (e.g., filter wheels) attached to the cold plate.