OPT-326 SYSTEM OPTIONS Cryostation Sample In Gas

Transcription

OPT-326 SYSTEM OPTIONS Cryostation Sample In Gas
SYSTEM OPTIONS
By L. Mauritsen
OPT-326
Cryostation Sample In Gas
Options
Revised August, 2012
The Sample in Gas Module is a powerful
tool for the Cryostation which allows
cooling of samples by gas conduction or solid
thermal conduction. Cooling of the Sample in Gas
Module is provided by the Cryostation 4K and 40K
stages. The module simply plugs into the sample space
of the Cryostation and thermal stages engage
automatically. Optical access is provided via four optical
ports in the sample area, and positioning of the sample
may be manually adjusted by rotating and translating
the sample rod.
Control of the Cryostation system operations and
sample temperature is completely automated, and the
gas space is controlled via a specifically designed user
interface. The sample space may be evacuated or
purged with gas and samples may be changed by
flowing helium gas and pulling out the sample rod. Since
the Sample in Gas Module can be easily removed, the
powerful functionality of the basic Cryostation can still
be utilized.
The Sample in Gas Module sits on the standard housing.
The module includes the 1st and 2nd stage links, which
are attached to the sample chamber. The sample rod
runs through the Sample in Gas Module and is inserted
through the glass insert at the top of the module. There
is a port on the Sample in Gas Module that may be
connected to a gas or vacuum pump. This allows the
user to control the gas content and the pressure of the
sample space.
Sample in Gas Module
151D Evergreen Drive, Bozeman, MT 59715 / USA TOLL FREE: 877-333-0959 / TEL: 406-551-2796 / [email protected]
www.montanainstruments.com
OPT-326 Sample in Gas Option
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The sample rod can be removed from the Sample in Gas
Module. There are several baffles along the length of
the sample rod to manage the thermal gradient from
the sample space to the top of the rod. The sample can
be mounted to the end of the sample rod using VGE or
bolts. The sample heater and thermometer run down to
the end of the sample rod providing accurate
measurement of the sample. The user may rotate the
sample rod with the sample attached while cold to
change the direction of the sample with respect to the
optical access. The sample may also be manipulated
vertically. There are 16 electrical feedthroughs at the
top of the sample rod and 10 are available for the user.
OPT-326
Sample space
The Sample in Gas Module uses a unique spring-link
technology which allows the module to be installed
easily with automatic and reliable coupling of the
thermal stages.
First Stage
Spring Link
Second Stage
Spring Link
Sample Rod
When inserting the sample rod, the sample plate on the
sample rod will key into a chamfer at the bottom of the
gas tube to allow solid conduction cooling of the sample
in addition to helium gas cooling. With the sample rod
keyed into the solid conduction chamfer there is
approximately 29mm diameter by 32.5mm height in the
sample chamber.
151D Evergreen Drive, Bozeman, MT 59715 / USA TOLL FREE: 877-333-0959 / TEL: 406-551-2796 / [email protected]
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OPT-326
Actual Results:
Temperature (K)
Sample in Gas Temperatures
6
5
Sample
4
Platform
3
Stage 2
2
Time (each tic is one minute)
Cool down
before
insertion
Temperature
stabilized
Experiments
with helium
Sample rod
fully inserted
10
Temperature during Helium Introduction
9
Temperature (K)
8
7
Sample
6
Platform
5
Stage 2
4
3
2
0
10
20
30
40
Time (min)
Sample at 3.7K
Helium introduced,
temperature rises as gas
heats chamber, then
cools back down
Helium flow turned
on, temperature
rises as gas heats
chamber, then cools
until helium
liquefies
Vacuum pump
turned on, sample
cools to 3.1K
System
warms up
151D Evergreen Drive, Bozeman, MT 59715 / USA TOLL FREE: 877-333-0959 / TEL: 406-551-2796 / [email protected]
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OPT-326
Sample in Gas System Cool Down Profile:
Note that the temperature stability is much less than 10mK.
151D Evergreen Drive, Bozeman, MT 59715 / USA TOLL FREE: 877-333-0959 / TEL: 406-551-2796 / [email protected]
OPT-326 Sample in Gas Option
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