EGAS41 - Swansea University
EGAS41 - Swansea University
EGAS41 - Swansea University
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41 st EGAS CP 71 Gdańsk 2009<br />
Metastability exchange optical pumping of 3 He gas at elevated<br />
pressure at 4.7 Tesla<br />
A. Nikiel 1,∗ , G. Collier 1 , B. G̷lowacz 1,2 , T. Pa̷lasz 1 , Z. Olejniczak 1,3 , W. Wȩglarz 3 ,<br />
G. Tastevin 3 , P.J. Nacher 3 , T. Dohnalik 3<br />
1 M.Smoluchowski Institute of Physics, Jagiellonian <strong>University</strong>, Reymonta 4,30-059 Cracow,<br />
Poland<br />
2 Laboratoire Kastler Brossel, Ecole Normale Superieure, 24 rue Lhomond, 75005 Paris, France<br />
3 Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342<br />
Cracow, Poland<br />
∗ Corresponding author: anna.nikiel@uj.edu.pl,<br />
The results of metastability exchange optical pumping of 3 He gas in the 32-267mbar<br />
pressure range performed in the magnetic field of 4.7 Tesla are reported for the first<br />
time. Comparing to previous data, the present experiments extend the pressure range<br />
by factor of 4, and the magnetic field range by almost factor of 2.5, probing the large<br />
parameter space in serch for optimal operating conditions.The optical pumping efficiency<br />
as a function of magnetic field for two pressures: 32 and 64 mbars in the same operating<br />
conditions (pump laser power 0.5 W and weak discharge) is shown in Fig 1, where the data<br />
obtained before [1] and in the present work are compiled. After almost linear increase<br />
of the steady state nuclear polarization M with magnetic field up to 2 T, a plateau is<br />
reached and a limiting value of 0.62 and 0.6 for 32 and 64 mbar, respectively, is achieved.<br />
The observed monotonic decrease of nuclear polarization with pressure is compensated<br />
by an increase of total magnetization, which to our knowleage is highest ever achieved<br />
by the method. This will put less demanding requirement for the final compresion stage,<br />
which is necessary in growing applications of highly polarized 3 He gas in magnetic resonance<br />
imaging of human lungs.<br />
6 0<br />
5 0<br />
M [ % ]<br />
4 0<br />
3 0<br />
2 0<br />
1 0<br />
0 . 0 0 0 . 7 5 1 . 5 0 2 . 2 5 3 . 0 0 3 . 7 5 4 . 5 0<br />
B [ T ]<br />
Figure 1: Steady-state polarization as a function of magnetic field B.<br />
References<br />
[1] A. Nikiel, et al., Eur. Phys. J. Spec. Top., 144, 2555 (2007)<br />
[2] E. Courtade, et al., Eur. Phys. J. D, 21, 25 (2002)<br />
[3] K. Suchanek, et al., J. Spec. Top., 144, 67 (2007)<br />
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