Compressing Spin-Polarized 3He With a Modified Diaphragm Pump

Nuclear spin-polarized 3He gas at pressures on the order of 100 kPa (1 bar) are required for several applications, such as neutron spin filters and magnetic resonance imaging. The metastability-exchange optical pumping (MEOP) method for polarizing 3He gas can rapidly produce highly polarized gas, but the best results are obtained at much lower pressure (~0.1 kPa). We describe a compact compression apparatus for polarized gas that is based on a modified commercial diaphragm pump. The gas is polarized by MEOP at a typical pressure of 0.25 kPa (2.5 mbar), and compressed into a storage cell at a typical pressure of 100 kPa. In the storage cell, we have obtained 20 % to 35 % 3He polarization using pure 3He gas and 35 % to 50 % 3He polarization using 3He-4He mixtures. By maintaining the storage cell at liquid nitrogen temperature during compression, the density has been increased by a factor of four.

[1]  P. Nacher,et al.  Accurate optical measurement of nuclear polarization in optically pumped 3He gas , 1992 .

[2]  F. Laloë,et al.  Optical pumping of helium with arc lamp excited LNA lasers , 1989 .

[3]  Stanley Bloom,et al.  Effects of Radiation Damping on Spin Dynamics , 1957 .

[4]  Mckeown,et al.  Spin-polarizing 3He nuclei with an arc-lamp-pumped neodymium-doped lanthanum magnesium hexaluminate laser. , 1993, Physical review. A, Atomic, molecular, and optical physics.

[5]  M. Schnall,et al.  Demonstration of a compact compressor for application of metastability‐exchange optical pumping of 3He to human lung imaging , 2000, Magnetic resonance in medicine.

[6]  E. Otten,et al.  A dense polarized 3He target based on compression of optically pumped gas , 1992 .

[7]  E. Otten,et al.  Study of mechanical compression of spin-polarized 3He gas , 1994 .

[8]  J. O’Hanlon.  A User's Guide to Vacuum Technology , 1980 .

[9]  Cummings,et al.  Optical pumping of Rb vapor using high-power Ga1-xAlxAs diode laser arrays. , 1995, Physical review. A, Atomic, molecular, and optical physics.

[10]  M. Bouchiat,et al.  Nuclear Polarization in He 3 Gas Induced by Optical Pumping and Dipolar Exchange , 1960 .

[11]  David Jones,et al.  High power , 1994, Nature.

[12]  J. R. Craig,et al.  Magnetic Field Uniformity around Near‐Helmholtz Coil Configurations , 1969 .

[13]  E. Otten,et al.  Interdisciplinary experiments with polarized 3He , 1998 .

[14]  S. V. Chernikov,et al.  1083 nm ytterbium doped fibre amplifier for optical pumping of helium , 1997 .

[15]  H. Carr,et al.  The Principles of Nuclear Magnetism , 1961 .

[16]  R. Welsh,et al.  Recent advances in spin-exchange pumped polarized 3He target technology , 1998 .

[17]  E. Otten,et al.  VERY LONG NUCLEAR RELAXATION TIMES OF SPIN POLARIZED HELIUM 3 IN METAL COATED CELLS , 1995 .

[18]  F. Laloë,et al.  Étude d'une nouvelle méthode permettant d'orienter, par pompage optique, des niveaux atomiques excités. Application à la mesure de la structure hyperfine de niveaux 1D de 3He , 1970 .

[19]  D. M. Schmidt,et al.  Diffusion Imaging with Hyperpolarized3He Gas , 1997 .

[20]  Gao,et al.  NMR calibration of optical measurement of nuclear polarization in 3He. , 1993, Physical review. A, Atomic, molecular, and optical physics.

[21]  F. Laloë,et al.  Résonance magnétique en champ de radiofréquence inhomogène - 2 e partie : Vérifications expérimentales ; mesure du coefficient de self-diffusion de 3He , 1974 .

[22]  Clifford J. Cremers,et al.  A User's Guide to Vacuum Technology , 1981 .

[23]  G. K. Walters,et al.  POLARIZATION OF He$sup 3$ GAS BY OPTICAL PUMPING , 1963 .

[24]  M. Bock.  Simultaneous T2* and diffusion measurements with 3He , 1997, Magnetic resonance in medicine.

[25]  E. Groves.  A Dissertation ON , 1928 .

[26]  G. K. Walters,et al.  Nature of Surface-Induced Nuclear-Spin Relaxation of Gaseous He 3 , 1969 .

[27]  G. K. Walters,et al.  NUCLEAR SPIN-LATTICE RELAXATION IN THE PRESENCE OF MAGNETIC-FIELD GRADIENTS , 1965 .

[28]  G. Tastevin.  Optically polarized helium-3 for N.M.R. imaging in medicine , 2000 .

[29]  J. Fowler,et al.  Journal of Research of the National Institute of Standards and Technology INFORMATION TECHNOLOGY FOR ENGINEERING AND MANUFACTURING Gaithersburg , MD June 12-13 , 2000 , 2000 .

[30]  W. Heil,et al.  3He neutron spin-filter , 1999 .

[31]  Arthur H. Firester,et al.  Design of Square Helmholtz Coil Systems , 1966 .

[32]  P. Nacher,et al.  High nuclear polarization in 3 He and 3 He- 4 He gas mixtures by optical , 1996 .

[33]  J. Szymanski,et al.  Neutron polarization with a polarized 3He spin filter , 1990 .

[34]  V. O. Altemose.  Helium Diffusion through Glass , 1961 .

[35]  Z. Chowdhuri,et al.  Test of 3He-based neutron polarizers at NIST , 2000 .

[36]  B. Hammouda,et al.  SANS Polarization Analysis with Nuclear-Spin-Polarized 3He , 2000 .

[37]  R. Timsit,et al.  An Experiment to Compress Polarized 3He Gas , 1971 .

[38]  T. Walker,et al.  Spin-exchange optical pumping of noble-gas nuclei , 1997 .

[39]  G.A.V. Sowter,et al.  Electrical and Magnetic Properties of Metals , 1964 .

[40]  F. Reif,et al.  Fundamentals of Statistical and Thermal Physics , 1965 .

[41]  L. Hedlund,et al.  MR Imaging with Hyperpolarized 3He Gas , 1995, Magnetic resonance in medicine.

[42]  George,et al.  Diffusion imaging with hyperpolarized 3He Gas , 1997, Journal of magnetic resonance.

[43]  David Pines,et al.  Relaxation Times in Magnetic Resonance , 1955 .

[44]  P. Tin,et al.  A high power, tunable, arc‐lamp pumped Nd‐doped lanthanum‐hexaluminate laser , 1990 .

[45]  Chupp,et al.  Laser optical pumping of high-density Rb in polarized 3He targets. , 1994, Physical review. A, Atomic, molecular, and optical physics.

[46]  Barton,et al.  Gaseous 3He-3He magnetic dipolar spin relaxation. , 1993, Physical review. A, Atomic, molecular, and optical physics.

[47]  P. Nacher,et al.  High nuclear polarization in3He and3He-4He gas mixtures by optical pumping with a laser diode , 1996 .

[48]  Y. Matsuda,et al.  Development of polarized 3He gas system as a spin analyzer for low energy neutrons , 1998 .

[49]  C. Jones,et al.  He→3(e→e′) quasielastic asymmetry , 1993 .

[50]  J. Liner,et al.  Determination of the Temperature Dependence of Gaseous Diffusion Coefficients Using Gas Chromatographic Apparatus , 1972 .