Tyrex-2
Polarised helium-3 filling station
The SEOP team on D3 in 1990: Francis Tasset, ???, ???, ???, Tim Chupp
©1990 ILL, S. Claisse
1st photo of COW just arrived at the ILL. Everyone smiles since the optics are intact. Left to right: Francis Tasset, Werner Heil and Hubert Humblot
©1996 ILL, Eddy-Lelièvre-Berna
Head of one of the "polarisation preserving compressor". The 1st one compressed the gas from 0.5 to a few tens of mbar, the second up to 5 bar, the pressure of the polarised 3He cells
©1996 ILL, Eddy Lelièvre-Berna
(jpg - 134 Ki)The principle of COW
©1997 Elsevier
The synoptic of COW
from Eddy Leliève-Berna's archives
COW before TYREX
A very first test of a 3He filter was performed at the ILL on D3 in 1990 [1] using the spin-exchange optical pumping (SEOP) method to polarise the gas. It was promising but the speed at which the polarisation decayed was much too fast. Hence a collaboration was started with the goal of producing a cheaper and more efficient 3He polariser.
In 1996, a first filling station for polarising 3He gas, nicknamed COW, was built at the ILL which used the metastability-exchange optical pumping (MEOP) technique. This was a collaboration with Mainz University [2,3].
The COW facility provided 60% nuclear-spin polarisation in cells of up to 5 bars pressure (250 cm3) at a production rate of about 0.5 bar•l/h.
References:
1- F Tasset, TE Chupp, JP Pique, A Steinhof, A. Rhompson, E Wasserman, M. Ziade (1992) Physica B: Condensed Matter, 180-181, 896-898. DOI: 10.1016/0921-4526(92)90502-J
2- F. Tasset (1995) Physica B 213&214, 935-938. DOI: 10.1016/0921-4526(95)00327-6
3- W. Heil, K.H. Andersen, D. Hofmann, H. Humblot, J. Kulda, E. Lelièvre-Berna, O. Schârpf, F. Tasset, (1997) Physica B, 241–243, 56-63. DOI: 10.1016/S0921-4526(97)00511-5