English   Nederlands   Deutsch   Español 
 Home   Experiment   News   Science   Sponsors     Internal 
Cooling tests have taken place over the last couple of weeks, first in Leiden and now again in Braunschweig where the whole experiment is currently lodging! Results of the cooling tests are important so that we know if the experiment and vacuum chamber can maintain the environment with which we would like to run our cold tests. The results of these tests are also important in terms of planning and preparation before the flight.

Below are the results of a cooling test performed in Leiden on 28-29 August. A postscript file is also available here. The information for all 8 sensors is given. The sensor maintaining a value around room temperature (~293 K) for the majority of the experiment appears to have broken a short time after the start of the experiment. The other distinctly different sensor was unattached to the experiment and simply recorded the environment in the chamber around the experiment during cooling and later while the experiment warmed up.
The test above was run on 29 August 2006 without the Pistons or the final Top Flange in place. Liquid nitrogen was fed through the Copper Tubing at the bottom of the experiment for 3 hours to achieve the final temperature of 80 K (-193 degrees Celsius). Once 80 K was recorded, the liquid nitrogen dewar was removed from the experiment and the temperature was monitored over night. After 14 hours with no liquid nitrogen to cool the system, the Thermocouples Sensors read a temperature for the experiment of just 150 K. In order to run our ice sample tests, the experiment must remain below 150 K for the duration of the flight, which is only 3 hours!! These were highly successful results that may mean we can prepare the experiment the night before the actual flight day! This would be extremely helpful to the team given the short preparation time in the morning before each flight. Still further tests are necessary.

After this promising result, the experiment traveled by mini-van and ferry to the laboratories at Strathclyde University where the Pistons and the Top Flange (built in Germany, see here), were assembled and the alignment tested (more information from Scotland ).The experiment then continued back to the European continent and the Technical University at Braunschweig, where the experiment will be completed.

In Braunschweig, with everything assembled, including the actual vacuum pumps we will use on board the flight, a repeat of the cooling and warming tests have just been performed so that 1) movement of the pistons can be checked, and 2) an overnight test of the vacuum sustainability and temperature changes when a vacuum pump is NOT in use. The second test is to investigate the possibility of cooling the experiment down the night before if no electrical power is available (as will probably be the case inside the plane where the experiment will be mounted during the flight week). The results of the overnight warming up testing (without a running vacuum pump) are below and a postscript file is available here.
Again, one sensor was not connected to the experiment, and this reading differs with respect to the other sensors. Still the temperature of the experiment, and the pressure readings (not shown), are shown to increase much more quickly. These are more readily compared to the Leiden tests below and here in postscript.
Some improvements are still planned for the setup, and preparation of the experiment the night before the flight will require slightly better results so that this can be achieved successfully.
Back to the NEWS page