# GENERAL

## EDUCATION and OUTREACH

**[NASA Fundamental Physics Research Supported by Undergraduates at the
College of Wooster]{.underline}**

Preliminary results from the NASA-funded fundamental physics experiment
at the College of Wooster to use the turbidity to measure the critical
exponent eta has appeared in the International Journal of Thermophysics,
volume 20, p. 877-887 (1999). The article is titled \"Measuring
turbidity in a near-critical, liquid-liquid system: a precise, automated
experiment\" and details the proof-of-performance of their computer
data-acquisition and control experiment. Authors on this paper are D.T.
Jacobs, S.M.Y. Lau, A. Mukherjee, and C.A. Williams. Stephanie Lau, a
summer research student at the College of Wooster, graduated with a B.S.
in physics from University of California, Berkeley in 1999. Anindya
Mukherjee received his B.A. in physics from the College of Wooster in
1997 and did his senior research project on this experiment. Carrie
Williams was another summer research student who has completed the
requirements for her B.A. in physics from College of Wooster, was
awarded a Barry M. Goldwater scholarship, and is completing a B.S. in
biomedical engineering at Washington University in St. Louis. Other
students are collaborating with Dr. Jacobs this summer as the experiment
continues.

FUTURE FLIGHT PROGRAM - ISSA PHASE I/II/III

#### BEST Laboratory Probe Has Initial Cooldown at JPL

Paul Finley, Yuanming Liu, and Feng Liu successfully performed the
initial cooldown for the Boundary Effect on Superfluid Transition (BEST)
experiment at JPL. They report that the experimental setup at JPL
successfully cooled down to helium temperature for the first time. The
system is free of vacuum leaks, the 1K fridge functions properly, and
all thermometers function as expected. In the coming weeks the team will
perform calibrations and stability tests on the overall thermal system.

The Best project has two teams, one at the University of California,
Santa Barbara headed by Principal Investigator Guenter Ahlers, the other
at JPL headed by Principal Investigator Feng Liu. This station at JPL is
intended to investigate science questions in the area of 2-dimensional
boundary effects, and to perform engineering testing in support of the
science work and science requirement formulation proceeding at UCSB.

ISSUES AND CONCERNS

#### LTMPE Project Suffers Changes in Direction 

The LTMPE project was informed verbally during the Payload Control
Board\'s review of the Integrated Payload Mission Model that Japan's
space agency NASDA cannot support unpressurized payloads on the HTV1
launch as requested by NASA for LTMPE. This forces the LTMPE project to
plan for an 11-month launch slip from July 2003 to June 2004, when HTV2
will launch. Several options will be considered on how to incorporate
this launch slip into the LTMPE development. Formal replan directions
were not discussed during the review.

SCIENCE HIGHLIGHTS

FUNDAMENTAL PHYSICS

**[Microgravity Dilution Refrigerator Described at Space Cryogenics
Workshop by Ames Group]{.underline}**

A paper presented at the 1999 Space Cryogenics Workshop in Quebec,
titled "Progress on a Microgravity Dilution Refrigerator" by Pat R.
Roach and Ben P. M. Helvensteijn, summarizes their recent results on
this technology development task at Ames Research Center. They report
that they have carried out a ground test of their single-cycle helium
dilution refrigerator in order to determine whether the use of porous
materials in the liquid chambers can properly control the location of
the helium liquids for use in microgravity. Such refrigerators use
mixtures of the liquid phase of the helium isotopes He-3 and He-4 and
can cool to temperatures below 0.02 K on the ground, where they depend
on gravity to keep the liquids in their proper chambers. With porous
materials in the liquid chambers, the Ames dilution refrigerator reached
temperatures below 0.06 K, well below the goal of 0.10 K. They were able
to tilt the operating refrigerator to angles of +/-16 degrees from
vertical, demonstrating the ability of the porous material to keep the
liquids in their correct positions. Operation of the refrigerator with
these tilts is convincing proof that the porous materials will enable
the refrigerator to operate in microgravity.

This success of the single-cycle refrigerator allows the development of
a continuously operating model, the most desirable type to support
fundamental physics experiments needing temperatures below 0.30 K. One
goal for such a refrigerator is to pre-cool a magnetic refrigerator that
can reach temperatures as low as 0.001 K where the properties of
superfluid He-3 can be studied. A number of fascinating microgravity
experiments has been suggested for this extremely interesting liquid.

**[Project SEE Wins East-West Collaboration Grant]{.underline}**

Principal Investigator Al Sanders of the University of Tennessee
announces that Project SEE (Satellite Energy Exchange) has recently
received two grants from NATA and NSF totaling \$20,000 for travel and
short-term living expenses to foster East-West collaboration.

For the past 7 years, US scientists in Project SEE have been
collaborating with a Moscow group of the Russian Gravitational Society
to develop ideas for a space experiment to investigate gravity forces.
Prof. Vitaly Melnikov, who is President of the Russian Gravitational
Society, heads this group.

UPCOMING EVENTS

1999 Cryogenic Engineering and International Cryogenic Materials
Conference July 12-16, 1999

Montréal, Québec, Canada

http://www.cec-icmc.org/Cec-icmc/about.htm