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Low Temperature and Condensed Matter Physics
    PRESENT: Ongoing Research
    FUTURE: BEST DYNAMX EXACT KISHT MISTE SUE SHE
    PAST: CHEX CVX LPE ZENO

Launch Date: : Flew November - December 1997 on STS-87 Columbia
Mission Duration: 2 weeks
Principle Investigator: Prof. John Lipa, Stanford University

 

Key Questions We Want to Answer:

Are there differences in behavior between a bulk quantity of a material, compared to a pancake-shaped mass of the same material, that are caused by moving it into the new shape? The Confined Helium Experiment (CHEX) tests theories about the differences in behavior of matter in three-dimensional and two-dimensional states. When liquid helium is supercooled it goes through a phase transition and becomes a superfluid, which gives it a new set of properties. Proving the Renormalization Group Theory, which works to explain how these transitions occur, is a priority for scientists.

What We Already Know:

CHEX measures how much heat is needed to get liquid helium to rise to certain temperatures when it is in different shapes and thickness. By measuring temperature rise it is possible to learn how the size and shape of the container changes the behavior of the material at the point of phase transition.

What We Hope to Find Out:


How We'll Conduct Our Experiment:

To create the experiment, liquid helium is placed between sheets of silicone inside a copper container. The container is placed in a large thermos bottle filled with even colder liquid helium to maintain its low temperature. When the experiment is taken into the microgravity of space, a heat pulse is applied and the material is measured to see how much power it takes to raise the temperature. Measurements are taken within one-tenth of a billion degree accuracy.


By operating experiments like CHEX in microgravity it is possible to use larger samples, which further increases accuracy. On Earth only a very small sample of the material can be tested.


Additional information :



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