The FTS Cold Stream Device
The FTS cold stream device can be used to keep samples at constant temperature in the range -10 to 30 °C.
The FTS system is mounted on a cart that can be moved to the various beamlines as needed. There are 2 systems which are almost identical. When they are not in use one system is at beamline 7-1 and the other is at beamline 9. To use the FTS system dismount the cryosystem by turning the thumbwheel on the black mounting plate that supports the cryocooler nozzle. You can turn down the nitrogen gas flow on the cryocooler but NEVER turn the flow all the way off. Ice will form inside the cooler if the nitrogen flow is completely stopped.
Mount the FTS system nozzle onto the mounting plate and tighten the thumbwheel. You may have to make some adjustments to the nozzle position. The nozzle should be 2-5 cm from the end of the capillary and the capillary should be in the center of the stream. There are micrometer stages that support the nozzle and these can be adjusted to center the nozzle. For beamline 7-1 the adjustments are minor, for the other beamlines you should consult an SSRL staff member before installing the FTS system.
Connect the green polyflow tubing to the flow meter labeled ?FTS? and set the flow to 50 SFCH. Then plug the system into electrical outlets inside the hutch. One of the units has separate power cords for the chiller and the controler the other uses only one cord to power both.
Turn on the FTS controller then turn on the refrigerator. To make the controller active press the “RUN” button. The green “RUN” LED should be lit. The controller will not control the gas stream temperature if the “RUN” LED is not lit. The controller has 3 displays, the top one shows the actual gas stream temperature as measured by a thermocouple in the nozzle. The middle one shows the value of whatever parameter is shown in the bottom display. Usually the middle display shows the set point (the desired temperature) and the lower display shows “ °C”. If it does not display “°C” push the lowest arrow button (the one pointing right) until it does.
The four buttons to the right are the preset values, if you press one the set point will be displayed in the middle display. The preset values are 1=10.0,2=4.0, 3=0.0 and 4=23.3 °C. Please do not change the preset values.
You can change the set point with the up and down arrows.This does not change the stored preset values however the new set point will remain in use until you press one of the preset buttons. So if you want a temperature different than any of the preset values select the preset value nearest the temperature you want and push the arrow keys until you get the value you want.
The “REM” button has no function on this controller.
The temperature should stabilize in ~15 minutes.
The temperature readout is calibrated to give the temperature at the crystal position when the end of the delivery tube is 5 cm from the sample position and the flow rate is 50 SCFH.
In order to prevent condensation inside the cooler it must be allowed to warm up before being disconnected from the gas flow.You can dismount the FTS system from the beamline and let it warm up while you continue to collect data with the cryostream.
Depress the "SP3" button to turn off the heater by setting the temperature to a low value. Turn the refrigeration unit off. The nitrogen gas should be left flowing while the cooler warms up. When the temperature display reads near room temperature turn the controller off. The nitrogen flow should then be turned off and the system disconnected.
Please return the system to beamline 7-1 when you are finished using it.
|Technical questions: Webmaster
questions: Henry Bellamy
|Last modified:Thursday, 29-Jul-2004 11:38:40 PDT.