A helium filled orifice type pulse tube refrigerator (OPTR) was designed, built and operated to provide cryogenic cooling.
To ascend, the pilot lets the helium fill the main chamber; to descend, the helium is compressed and sent back into the tanks, enabling the chamber to fill with air.
The additional hardening at high helium concentrations was associated with the presence of helium filled cavities (bubbles), observed by transmission electron microscopy (TEM).
The heart of the system, the SQUID-based magnetic field detector, is sitting inside a liquid- helium filled low-noise fiber glass Dewar [see Fig. 1(a) and (b)]44,45.
Even if we reduced the weight of the parts mounted under the balloon as much as we could, we had to use very big volume of helium filled balloon to lift up the airship.
The purchaser has to obtain from the Dept. of Interior, a 3-page application to Purchase Helium, fill it out with details of how he intends to use it, swear to it before a notry, and send it to the Bureau of Mines.
A full evaluation of the experiment was performed during a test flight occurring between 28 December 2000 and 13 January 2001 where ATIC was carried to an altitude of ∼37 km above Antarctica by a ∼850,000 m3 helium filled balloon for one circumnavigation of the continent.
Analysis showed different hard disk drive optimization for helium filled HDDs versus those filled with air, particularly for adjacent track interference (ATI) versus track mis-registration (TMR).
While a helium filled balloon is pushed down by the wind (one of the biggest problems for aerostats), kites are pushed up.
Hoya, a maker of glass disk substrates had a talk where they discussed using 3.5-inch glass rather than aluminum disks in a Helium filled drive, offering a capability to go to 10 and possibly 12 disks in the conventional 3.5-inch form factor HDD.
