[go: up one dir, main page]

WO2009143368A2 - Cellule de stockage non cryogénique pour <sp>129</sp>xe hyperpolarisé - Google Patents

Cellule de stockage non cryogénique pour <sp>129</sp>xe hyperpolarisé Download PDF

Info

Publication number
WO2009143368A2
WO2009143368A2 PCT/US2009/044884 US2009044884W WO2009143368A2 WO 2009143368 A2 WO2009143368 A2 WO 2009143368A2 US 2009044884 W US2009044884 W US 2009044884W WO 2009143368 A2 WO2009143368 A2 WO 2009143368A2
Authority
WO
WIPO (PCT)
Prior art keywords
spin
gaseous
storage
polaπzed
relaxation
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US2009/044884
Other languages
English (en)
Other versions
WO2009143368A3 (fr
Inventor
Brian T. Saam
Geoffrey Schrank
Benjamin C. Anger
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
University of Utah
Original Assignee
University of Utah
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by University of Utah filed Critical University of Utah
Publication of WO2009143368A2 publication Critical patent/WO2009143368A2/fr
Publication of WO2009143368A3 publication Critical patent/WO2009143368A3/fr
Anticipated expiration legal-status Critical
Priority to US13/188,246 priority Critical patent/US20120160710A1/en
Ceased legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/282—Means specially adapted for hyperpolarisation or for hyperpolarised contrast agents, e.g. for the generation of hyperpolarised gases using optical pumping cells, for storing hyperpolarised contrast agents or for the determination of the polarisation of a hyperpolarised contrast agent
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/44—Arrangements or instruments for measuring magnetic variables involving magnetic resonance using nuclear magnetic resonance [NMR]
    • G01R33/48—NMR imaging systems
    • G01R33/54—Signal processing systems, e.g. using pulse sequences ; Generation or control of pulse sequences; Operator console
    • G01R33/56—Image enhancement or correction, e.g. subtraction or averaging techniques, e.g. improvement of signal-to-noise ratio and resolution
    • G01R33/5601—Image enhancement or correction, e.g. subtraction or averaging techniques, e.g. improvement of signal-to-noise ratio and resolution involving use of a contrast agent for contrast manipulation, e.g. a paramagnetic, super-paramagnetic, ferromagnetic or hyperpolarised contrast agent

Definitions

  • This disclosure is related to the storage of spin polarized (e.g. hyperpolarized) gasses (e.g. 129 Xe).
  • spin polarized gasses e.g. 129 Xe
  • Noble-gas isotopes having non-zero nuclear spin may be optically polarized to levels approaching unity via the techniques such as of spin-exchange optical pumping (SEOP) [1, 2], whereby the notoriously weak signal generated by nuclear moments is enhanced by several orders of magnitude.
  • SEOP spin-exchange optical pumping
  • circularly polarized laser light is incident on a glass cell containing a macroscopic amount of an alkali-metal (usually Rb), the noble gas, and a small quantity of nitrogen to promote collisional de-excitation of the excited states generated by resonant absorption of the laser light by the alkali-metal vapor at the first principle (D 1 ) electric-dipole transition [6]. (This corresponds to a wavelength of 795 nm for Rb.)
  • the alkali-metal vapor density is controlled by adjusting the cell temperature from room temperature up to —500 K in the presence of a macroscopic amount of alkali metal in the closed cell.
  • ⁇ ⁇ / + ⁇ / , + ⁇ , + ⁇ W ,
  • T 0 293 K
  • [B] is the density of a second gas in the mixture
  • r ⁇ k B /k Xe is the ratio of the persistent-dimer breakup coefficient for the second gas to that for xenon
  • r 0 51 for nitrogen, which, along with helium, is most often present with xenon in SEOP situations
  • m Eq (3) is based on the results of Moudrakovski, et al [13], we have estimated its temperature dependence by conside ⁇ ng that, in the weak-mteraction limit, the probability for a spin transition is approximately proportional to the rate of binary collisions and to the square of the collision duration
  • T 1 oc l/v where v ⁇ T 112 is the mean thermal velocity of the xenon atoms
  • Hyperpola ⁇ zed l29 Xe is now used for research variety of disciplines such as medical imaging, biological assays, and pore characterization [IA, 2A, 3A] Many of these experiments require on-demand production of large (hter-per-hour and more) quantities of hyperpolarized 129 Xe The state-of-the-art method for such production is the flow-through polanzer/accumulator [4 A, 5A]
  • One manufacturer claims the ability to produce 10 L/h of hyperpola ⁇ zed xenon [6A] These techniques require diluting Xe to a small percent of gas mixture, usually of order 1%
  • cryogenic freezing This method capitalizes on the high Xe melting temperature (161 K) compared with other gasses m the mixtuie Xenon freezes out of the gas stream as a polycrystalline solid and deposits in some holding cell, the hyperpolanzation generally survives the phase transition
  • the cryogenic cell is also used to store the Xe, as the relaxation time of Xe at 77 K in an applied field of 2 kG is of order 2 hours [7A]
  • the xenon can be accumulated and stored as a solid for about this amount of time before it is revolatihzed and used as a gas in an experiment or application
  • Cryogenic separation is disadvantageous because it is a stepped method One must accumulate Xe for some amount of time from a flow through polarizer and then divert or stop the flow when ready to volatilize the solid It would advantageous for a number of expe ⁇ ments to have the ability to separate the Xe continuously, so that a steady stream of pure hyperpolarized Xe could be directed to an expe ⁇ ment or application Further disadvantantages of cryo separation are discussed below
  • an apparatus may include a large (10 cm diam or larger) valved glass container (cell), the interior of which is coated with a silicone or paraffin-like compound to inhibit longitudinal relaxation of the 129 Xe nuclei
  • the cell contains no alkali- metal
  • the cell sits in a modest magnetic field (about 3 millitesla) generated by a Helmholtz coil parr
  • the cell is designed to receive HP xenon gas from a current state-of-the-art device, a 129 Xe flow-through polarizer/accumulator based on the established method of spin exchange optical pumping, whereby laser light and an alkali-metal vapor are used to transfer spin angular momentum to 129 Xe m the gas phase
  • the inventors have developed a thorough understanding of gas-phase relaxation of 129 Xe nuclei m the presence of other xenon atoms (intrinsic relaxation), as well as due to collisions with the
  • a storage apparatus for non-cryogenically storing gaseous spin polarized " Xe including a storage vessel including an interior surface substantially surrounding a storage volume, and a magnet which produces a substantially uniform magnetic field within the storage volume, where the interior surface is characte ⁇ zed in that the longitudinal spin relaxation rate of the gaseous spin polarized 129 Xe due to interactions with the interior surface is about equal to or less than the longitudinal spin relaxation rate of the gaseous spin pola ⁇ zed 129 Xe due to intrinsic mechanisms
  • Some embodiments include a heater for maintaining the storage vessel at a temperature greater than room temperature In some embodiments, the heater is configure to maintain the storage vessel at a temperature greater than about 100 degrees centigrade
  • the magnet includes a pair of coils in the Helmholtz configuration
  • the inte ⁇ or surface consists of a layer of mate ⁇ al substantially free of alkali-metal
  • the vessel includes glass, and the interior layer is on the glass In some embodiments, the interior layer includes a silane- or siloxane-based coating
  • the vessel includes a plastic mate ⁇ al and the interior surface consists of the plastic mate ⁇ al
  • the plastic material includes Teflon
  • the ratio of the area of the interior surface to the storage volume is less than about 1 cm ' In some embodiments, ratio of the area of the inte ⁇ or surface to the storage volume is less than about 0 5 cm '
  • the substantially uniform magnetic field within the storage volume has a magnitude of about 3 milliTesla or less
  • the storage vessel is characterized by a relaxation time for the gaseous spin pola ⁇ zed 129 Xe of greater than about five hours, the relaxation tune corresponding to a density of the spin polanzed 129 Xe of greater than about one amagat
  • the storage vessel is characte ⁇ zed by a relaxation time for the gaseous spin pola ⁇ zed 129 Xe of greater than about seven hours, the relaxation time corresponding to a density of the spin polarized 129 Xe of greater than about one amagat
  • a system for producing and storing gaseous spin pola ⁇ zed 129 Xe including a polarizer configured to produce gaseous spin polarized 129 Xe, and a storage apparatus for non-cryogemcally sto ⁇ ng gaseous spin polarized 129 Xe as desc ⁇ bed above
  • the storage apparatus is in communication with the polarizer to receive and store the spin polarized 129 Xe
  • the pola ⁇ zer is a spin exchange optical pumping pola ⁇ zer
  • the polarizer includes one or more volumes in which Xe is m the presence of alkali-metal, and the storage apparatus stores the gaseous spin pola ⁇ zed 129 Xe received from the pola ⁇ zer in a substantially alkali-metal free environment
  • Some embodiments include a gas centrifuge separator
  • the separator is m communication with the pola ⁇ zer to receive a mixture of gaseous spin pola ⁇ zed 129 Xe and other gasses from the pola ⁇ zer
  • the separator is configured to separate substantially pure gaseous spin pola ⁇ zed 129 Xe from the mixture
  • the storage apparatus is in communication with the separator to receive and store the substantially pure gaseous spin pola ⁇ zed P9 Xe
  • the substantially pure gaseous spin pola ⁇ zed 129 Xe is at least about 90% pure In some embodiments, the substantially memee gaseous spin pola ⁇ zed ' 29 Xe is substantially free of alkali-metal
  • 129 Xe is disclosed including providing storage vessel including an interior surface substantially surrounding a storage volume, providing a substantially uniform magnetic field within the storage volume, and introducing gaseous spin polarized 129 Xe into the storage volume
  • the interior surface is characte ⁇ zed in that the longitudinal spin relaxation rate of the gaseous spin polarized 129 Xe due to interactions with the interior surface is about equal to or less than the longitudinal spin relaxation rate of the gaseous spm pola ⁇ zed 129 Xe due to intrinsic mechanisms
  • Some embodiments include maintaining the storage vessel at a temperature greater than room temperature In some embodiments, the temperature greater than room temperature is greater than 100 degrees centigrade or greater than 200 degrees centigrade, or more
  • introducing gaseous spin pola ⁇ zed 129 Xe into the storage volume includes polarizing gaseous 129 Xe m a pola ⁇ zer to produce gaseous spin pola ⁇ zed 129 Xe and transferring the gaseous spin pola ⁇ zed 129 Xe to the storage vessel
  • transfer ⁇ ng the gaseous spm pola ⁇ zed 129 Xe to the storage vessel includes passing a mixture of gaseous spm polarized 129 Xe through one or more gas centrifuge separators to produce substantially pure gaseous spin polarized 129 Xe, and introducing the substantially pure gaseous spin pola ⁇ zed 129 Xe into the storage volume
  • the centrifuge is configured separate polarized xenon without substantially destroying the polarization
  • Various embodiments may include any of the above desc ⁇ bed features, either alone or m combination
  • Fig IA is a schematic of a cell for non-cryogenic storage of gaseous spin pola ⁇ zed 129 Xe
  • Fig IB a schematic of a system for producing and sto ⁇ ng gaseous spin polarized 129 Xe
  • Fig 1C is a flow diagram of a process for producing and storing gaseous spm pola ⁇ zed 129 Xe
  • Fig l is a plot of persistent dimmer relaxation rate versus total gas density
  • Fig 2 shows a plot of 2K(M sr + M csa ) extracted from the fits in Fig 1 (see Table I) vs the square of the applied magnetic field B 0
  • Fig 3 is a plot of the 129 Xe persistent-dimer relaxation rate F 0 at 8 0 T vs I /T 2
  • Fig 4 is a plot of NMR signal mtensity vs time for cell 113B at room temperature in an applied field of 14 I T
  • Fig 5 shows a plot of T w vs B 0 at room temperature
  • Fig 6 shows pressure profiles m stages of the cent ⁇ fugation process, for 1 stage (A), 3 stages (B), 5 stage(C), and 8 stages (D) of cent ⁇ fugation
  • Fig 7 shows the time evolution of the concentration of Xe gas in a cylinder
  • Figs 8a-8g are photographs showing exemplary storage cells DETAILED DESCRIPTION
  • Fig IA shows a storage cell 100 or non-cryogemcally storing gaseous spin polarized l29 Cell 100 includes a storage vessel 102 including an interior surface 104 substantially surrounding a storage volume 106 Storage volume 106 may be accessed using valve 107
  • a magnet 108 produces a substantially uniform magnetic field within the storage volume 106
  • the magnet 108 is an electromagnet which includes a pair of coils m the Helmholtz configuration, d ⁇ ven by power source 110 hi other embodiments, and suitable type of magnet may be used including e g a permanent magnet or an electromagnet m another configuration (e g a solenoid surrounding all or a portion of vessel 102) hi some embodiments, the substantially uniform magnetic field withm the storage volume has a magnitude of about 3 milliTesla or less, or about 1 milliTesla or less
  • interior surface 104 is made of a material which inhibits longitudinal spm relaxation caused by mteractions (e g collisions) between the 129 Xe and the surface
  • surface 104 is characterized in that the longitudinal spin relaxation rate of the gaseous spin polarized 129 Xe stored in volume 106 due to interactions with the interior surface is about equal to or less than the longitudinal spin relaxation rate of the gaseous spin polarized 129 Xe due to intrinsic mechamsms
  • the interior surface 104 is wholly or partially made up of material which is substantially free of alkali-metal
  • the vessel 102 may be made of glass, and the interior surface 104 may be mate ⁇ al layer on the glass
  • the mate ⁇ al layer includes a silane- or siloxane-based coating Suitable coatings may be provided using any techniques know in the art
  • the vessel 102 is made of an alkali-metal free plastic mate ⁇ al (e g Teflon) and the mte ⁇ or surface 104 consists of this plastic mate ⁇ al (e g no coating is provided on the layer)
  • cell 100 include a heater 112 for maintaining the storage vessel at a temperature greater than room temperature
  • the heater 112 may operate to heat vessel 102 using any suitable method including contact heating, convection heating, radiative heating, etc
  • Heater 1 12 may include a control system, e g a thermostat for maintaining a set temperature
  • the heater 112 maintains the storage vessel at a temperature, e g , greater than room temperature, or greater than about 1 OO degrees centigrade, 200 degrees centigrade, 300 degrees centigrade, or more
  • the vessel 102 is a spherical bulb, in various embodiments the vessel 102 may be formed as any suitable shape As desc ⁇ bed m detail below, it is advantageous to minimize the ratio of the area of the interior surface 104 to the storage volume 106 For example In some embodiments, the ratio of the area of the interior surface to the storage volume is less than about 1 cm ', less than about 0 5 cm ', or even less Figs 8a through 8g show exemplary vessels having various dimensions
  • Cell 100 can be used for long term, non-cryogemc storage of gaseous spin pola ⁇ zed 1 29 Xe
  • the use of an alkali free interior surface and applied the magnetic field reduces ext ⁇ nsic relaxation, and allows for long storage times
  • the storage vessel is characterized by a relaxation time for the gaseous spin pola ⁇ zed 129 Xe of greater than about five hours, greater than about seven hours, or even more at a of greater than about one amagat or more
  • a system 200 may be used for producing and storing gaseous spin pola ⁇ zed 129 Xe
  • System 200 includes a polarizer 202 which operates on gas mix 203 to produce gaseous spin polarized 129 Xe
  • the pola ⁇ zer 202 is a spin exchange optical pumping pola ⁇ zer, e g of the type desc ⁇ bed m detail below
  • the pola ⁇ zer may include one or more volumes in which Xe is in the presence of alkali-metal, while storage cell 100 stores the gaseous spin polarized 129 Xe received from the pola ⁇ zer m a substantially alkali-metal free environment
  • Any suitable system e g system of valves and transfer chambers, may be employed to transfer the spin pola ⁇ zed 129 Xe from the polanzer 202 to the storage cell 100 while maintaining the alkali free environment of the cell 100
  • separator 204 which may be a gas centrifuge separator
  • the separator 204 is m communication with the polarizer 202 to receive a mixture of gaseous spin pola ⁇ zed 129 Xe and other gasses from the pola ⁇ zer 202
  • the separator 204 separates substantially pure gaseous spin pola ⁇ zed 129 Xe from the mixture
  • the separator 204 may operate to effect the separation without substantially reducing the spin polarization of the polarized 129 Xe
  • the separator 204 may be constructed with substantially alkali-metal free inner surfaces to reduce ext ⁇ nsic relaxation resulting from collisions of the gas with these surfaces
  • the storage cell 100 is m communication with the separator 202 to receive and store the substantially pure gaseous spin pola ⁇ zed 129 Xe
  • the substantially pure gaseous spin polarized 129 Xe may be at least about 80%, about 90% pure, about 95% pure, about 99% pure, or more
  • the substantially pure gaseous spin polarized ' 29 Xe transferred to cell 100 is substantially free of alkali-metal
  • Fig 1C shows a flow diagram illustrating steps for a process 300 of polarizing and sto ⁇ ng 129 Xe using the system 200
  • pola ⁇ zer 202 receives an un-pola ⁇ zed gas mix 203 contaimng Xe
  • pola ⁇ zer 202 polarizes at least portion of the gas mix to produce gaseous spm pola ⁇ zed 129 Xe
  • separator 204 separates the gaseous spin pola ⁇ zed 129 Xe from other gasses present in the mix 203
  • the gaseous spin polarized 129 Xe is stored in storage cell 100
  • Step 304 may include the following substeps hi substep 304a, the gaseous spin polarized 129 Xe is contained m the alkali-metal free environment of vessel 102
  • substep 304b and 304c a desired magnetic field and temperature is maintained m the vessel 102
  • k Xe and & N are the breakup coefficients for xenon and nitrogen as third bodies, respectively
  • Hyperpola ⁇ zed xenon was generated m one of several "pumping" cells, which have a geometry similar to the measurement cells and also contain Rb metal for SEOP
  • Xenon gas, polarized by SEOP to « 10 % m a pumping cell was then transferred (at the known value of a ) to the measurement cell usmg a glass transfer manifold and mechanical vacuum pump for evacuating dead space
  • the cell was immediately inserted into a NMR probe and the probe assembly was inserted mto the magnet
  • the pola ⁇ zed measurement cell was transported in a portable 2 mT battery-powered solenoidal coil to an NMR facility (Less than 10% of the magnetization was lost du ⁇ ng transport )
  • All magnets (with the exception of the 1 5 T magnet) had a wide-bore (89 mm diam) vertical configuration
  • the probes were capacitively tuned saddle coils (one to two turns) placed along the stem of the cell, the respective resonance frequencies corresponded to the 129 Xe gyromagnetic ratio of 11 8 MHz/T In the 1 5 T field (provide
  • Infimtyplus 600 (14 1 T) For measurements above room-temperature, the 8 0 T probe was insulated and heated with air flowing across a filament heater located away from the magnet In addition, several low -field ( B 0 « 3 mT) measurements were made using a homebuilt low-frequency spectrometer [33], whereby the cell and NMR probe were placed m a oven (similarly heated with flowing hot air) located at the isocenter of a Helmholtz pair
  • the relaxation rate T was measured as a function of total gas density [G] for the four different magnetic fields
  • the data were fit m each case to Eq (5) using the appropriate value of the Larmor frequency ⁇ , with the wall-relaxation rate T w and the interaction- strength term 2K(M sr + M csa ) extracted as free parameters, see Table 1 Since the xenon concentration a and, hence, the breakup coefficient k a are field-mdependent, the value
  • the wall relaxation rate T w and the product 2K(M sr + ⁇ / csa ) are extracted from fits of the measured relaxation rates F([G]) to Eq (5) for each field (see Table 1)
  • the corresponding value of T w has been subtracted from all the data sets in this plot to show clearly the behavior of the persistent-dimer rate T
  • the high-density fast- fluctuation limit results m a density-independent relaxation rate (asymptote) that increases with field due to the increasing strength of the CSA interaction, the magnetic suppression of the persistent-dimer mechanism with decreasing density starts at higher densities and happens more gradually for higher fields
  • the field-independent molecular breakup coefficient k a (3 54 ⁇ 0 28) x l O ⁇ 10
  • the errors m the free parameters were, in general, underestimated by our non-lmear fitting routines and had to be handled with some care They were determined for a given field and temperature by allowing k a to vary over its error range and observing the effect m the fit on 2K(M sr + M csa ) and T w Table I Free parameters extracted from the fits of the data shown in Fig 1 to Eq (5) Errors are given m parentheses for the least significant figure(s)
  • 2K(M sr + M csa ) is plotted vs the square of the applied field B 0 m Fig 2 Fig 2 shows a plot of 2K(M sr + M csa ) extracted from the fits m Fig 1 (see Table I) vs the square of the applied magnetic field B 0
  • a linear fit to the data yields the relative contributions of the SR and CSA interactions as a function of B 0 , as given in Eqs (9) and (10), where the intercept is proportional to the field-independent spin-rotation interaction strength M sr , which can then be used to deduce the limiting low-field pure-xenon relaxation rate due to persistent dimers
  • Fig 3 is a plot of the 129 Xe persistent-dimer relaxation rate Y p at 8 0 T vs MT 2 , where the absolute temperature T ranges between 293 K and 373 K
  • the measured rates were corrected by subtracting the relatively small room-temperature wall-relaxation rate T w
  • the quality of the one-parameter fit forced through the ongm indicates that this simple inverse- square model for the temperature dependence of T based on the arguments presented herein is reasonably valid at and above room temperature
  • the corrected data are plotted m Fig 3 vs the inverse-squared absolute temperature
  • the one-parameter least-squares linear fit to this data supports the simple theory of a linear dependence of the persistent-dimer relaxation rate on l/T 2 , which comes from the temperature dependence of the product Kr p in the fast-fluctuation limit of Eq (4)
  • the slope of fitted line is 6 2 ⁇ 0 2 s ⁇ ' K 2
  • the slope can be corrected for the low-field limit by multiplying by 81 %, the fraction of the interaction strength due to SR at 8 0 T (see end of previous section and Fig 1 )
  • Using the corrected slope to calculate F at T 293 K yields 5 85 x lO ⁇ 5 s " ' , m good agreement with the minimum relaxation rate for pure xenon given m Eq (12)
  • Fig 4 is a plot of NMR signal intensity vs time for cell 113B at room temperature m an applied field of 14 1 T
  • the cell contains xenon at 12 0 mbar and nitrogen at 1 09 mbar To our knowledge, this is by far the longest gas-phase relaxation time ever recorded for 179 Xe and results from the simultaneous suppression of the intrinsic persistent-dimer mechanism and the wall-relaxation mechanism at 14 1 T
  • T x 105 h for the first 50 h and T x - 82 h for the last 45 h This may have to do with a gradual increase in oxygen concentration (due to very slow outgassmg or leakage) into the cell over the course of the long measurement If this gi adual increase in relaxation rate were due solely to collisions with paramagnetic oxygen atoms, it would correspond to an oxygen partial pressure of « 10 ⁇ 3 mbar [34] developmg over the course of the measurement
  • Fig 4 Plot of NMR signal intensity vs time for cell 113B at room temperature in an applied field of 14 1 T
  • the cell contains xenon at 12 0 mbar and nitrogen at 1 09 mbar To our knowledge, this is by far the longest gas-phase relaxation time ever recorded for 129 Xe and results from the simultaneous suppression of the intrinsic persistent-dimer mechanism and the wall-relaxation mechanism at 14 1 T
  • Fig 5 shows a plot of T w vs B 0 at room temperature
  • data were acquired for three additional values of the applied field B 0 made m an electromagnet (0 91 T, and 2 0 T) and a Helmholtz pair (2 8 mT)
  • T w was not extracted from a fit
  • cell 113B was filled with nearly pure xenon (a « 1 ) from a flow-through xenon polarizer (built in our laboratory) to a density « 1 ama
  • Table II shows low-field relaxation times (in hours) of four cells at both room temperature and 100 0 C.
  • the cells all contained pure xenon at the indicated density (in amagats). Uncertainties are given in parentheses for the least significant figure(s). The last two columns show the room- temperature wall-relaxation time derived from subtracting the relevant persistent- and transient-dimer rates [Eq. (3)] from the measured rate. The elevated temperature increases the measured T x by 50-100%.
  • the size will eventually be limited by magnetic field gradients far away from the center of a pair of Helmholtz coils, but this limit is not notably stringent for xenon.
  • Helmholtz pair of radius (and separation) R and a cell having radius no larger than R/3 We have estimated the gradient-induced relaxation for such a cell to be [36]
  • non-cryogenic storage does not allow for easy separation of 129 Xe from other gasses through cryogenic solidification
  • Gas-centrifuge separation may be used m conjunction with a non-cryogenic storage cell to provide purification This is a process where separation is brought about by rotating the gasses at high speed Gasses with higher molecular weights are pushed to the walls of the centrifuge, while lighter gasses remain m the center This is usually done in a continuous-flow mode
  • Gas centrifuges have been used to separate uramum isotopes for use m nuclear fission [8A]
  • Centrifuge devices are most effective when using an axial countercurrent flow, whereby one gams both enhanced separation and shorter equilibrium times [9A]
  • the radial partial pressures of gasses in a centrifuge are given by [10A]
  • R is the radius the centrifuge chamber.
  • the intial gas mixture is composed of 1 % Xe, 10% N , , and 89% He. Xe is in grey, N 2 is in black, and He is in lighter grey.
  • the gas mixture will quickly gain angular momentum and establish a pressure gradient. Diffusion will then establish the equilibrium concentration profile.
  • Centrifuge gas separation of hyperpola ⁇ zed ' 29 Xe from flow-through systems is a feasible alternative to cryogenic separation
  • the above analysis indicates that one could reasonably ennch an initial 1% Xe mixture to > 90% purity using 8 centrifuge stages m about 8 minutes
  • a suitable high-strength material could be coated with a silane- or siloxane-based coating, such as those used with glass polarization cells [12A, 13A], or with some other suitable non- relaxive coating
  • the storage cells descnbed above are made of glass with an intenor coating free of alkali-metals
  • any material may be used which is characterized m that the longitudinal spin relaxation rate of the gaseous spm pola ⁇ zed 129 Xe due to interactions with the interior surface (the wall rate) is about equal to or less than the longitudinal spin relaxation rate of the gaseous spin polarized 129 Xe due to intrinsic mechanisms
  • plastic materials e g fluoropolymer plastics
  • Teflon of Ultem 1000 should have a wall rate comparable to or less than that of the coated glass surfaces used in the examples above
  • storage cells may be maintained at temperatures of, for example, a few hundred degrees centigrade or more to provide improved performance In general, this operating temperature is limited only by the mate ⁇ al properties (e g melting point) of the storage cell
  • a field may be provided with any suitable strength, e g 3 mT or more, 100 mT or more, 1000 mT or more, etc. In general, increased field strength will improve the performance of the storage cell by decreasing the hyper-pola ⁇ zation relaxation rate
  • hyperpolarized gasses including but not limited to medical imaging (e g medical MRI)
  • storage cells of the type desc ⁇ bed above may be used m conjunction with a cryogenic apparatus used for separation of hyperpolarized xenon, but not for storage
  • a cryogenic apparatus used for separation of hyperpolarized xenon
  • the devices and techniques desc ⁇ bed herein may be extended to the non-cryogenic storage of hyperpolarized materials other than I 29 Xe, e g any other mate ⁇ al which expe ⁇ ences inhibited wall relaxation in an alkali free environment

Landscapes

  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Magnetic Resonance Imaging Apparatus (AREA)
  • Chemical Vapour Deposition (AREA)

Abstract

L'invention concerne un système pour produire et stocker du 129Xe polarisé de spin gazeux qui comprend : un polariseur configuré pour produire du 129Xe polarisé de spin gazeux, et un appareil de stockage pour stocker de façon non cryogénique du 129Xe polarisé de spin gazeux.
PCT/US2009/044884 2008-05-23 2009-05-21 Cellule de stockage non cryogénique pour <sp>129</sp>xe hyperpolarisé Ceased WO2009143368A2 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US13/188,246 US20120160710A1 (en) 2008-05-23 2011-07-21 Non-cryogenic storage cell for hyperpolarized 129xe

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US5581908P 2008-05-23 2008-05-23
US61/055,819 2008-05-23

Related Child Applications (2)

Application Number Title Priority Date Filing Date
US12994326 A-371-Of-International 2009-05-21
US13/188,246 Continuation US20120160710A1 (en) 2008-05-23 2011-07-21 Non-cryogenic storage cell for hyperpolarized 129xe

Publications (2)

Publication Number Publication Date
WO2009143368A2 true WO2009143368A2 (fr) 2009-11-26
WO2009143368A3 WO2009143368A3 (fr) 2010-02-25

Family

ID=41340898

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2009/044884 Ceased WO2009143368A2 (fr) 2008-05-23 2009-05-21 Cellule de stockage non cryogénique pour <sp>129</sp>xe hyperpolarisé

Country Status (2)

Country Link
US (1) US20120160710A1 (fr)
WO (1) WO2009143368A2 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019005537A1 (fr) * 2017-06-30 2019-01-03 Avx Corporation Dissipation de chaleur à partir d'un circuit d'équilibrage pour un module ultracondensateur

Family Cites Families (39)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4417909A (en) * 1978-12-04 1983-11-29 Airco, Inc. Gas separation process
US4450407A (en) * 1981-10-02 1984-05-22 Litton Systems, Inc. Magnetic resonance cell and method for its fabrication
US4793357A (en) * 1986-11-24 1988-12-27 Picker International, Inc. CT blood flow mapping with xenon gas enhancement
US4971258A (en) * 1988-08-26 1990-11-20 Ihi Master Metal Ltd. Method of making high-purity fine particles of reactive metals and manufacturing vessel therefor
US5039500A (en) * 1988-11-18 1991-08-13 Kyodo Oxygen Co., Ltd. Process for producing xenon
US5545396A (en) * 1994-04-08 1996-08-13 The Research Foundation Of State University Of New York Magnetic resonance imaging using hyperpolarized noble gases
US5617860A (en) * 1995-06-07 1997-04-08 Smithsonian Astrophysical Observatory Method and system for producing polarized 129 Xe gas
US5612103A (en) * 1995-06-07 1997-03-18 Princeton University Coatings for production of hyperpolarized noble gases
US5617859A (en) * 1995-10-02 1997-04-08 General Electric Company Apparatus and methods for magnetic resonance (MR) imaging of cavities using fluids polarized at low temperatures
US5809801A (en) * 1996-03-29 1998-09-22 The Trustees Of Princeton University Cryogenic accumulator for spin-polarized xenon-129
US5642625A (en) * 1996-03-29 1997-07-01 The Trustees Of Princeton University High volume hyperpolarizer for spin-polarized noble gas
WO1997037239A1 (fr) * 1996-03-29 1997-10-09 Lawrence Berkeley National Laboratory Amelioration de la rmn ou de l'irm par la presence de gaz nobles hyperpolarises
DE19635002A1 (de) * 1996-08-30 1998-03-05 Messer Griesheim Gmbh Verfahren zur Online-Rückgewinnung von Xenon aus Narkosegas
US5934103A (en) * 1997-04-22 1999-08-10 Northrop Grumman Corporation Method and apparatus for production of spin-polarized medical-grade xenon 129 gas by laser optical pumping
US6085743A (en) * 1997-05-30 2000-07-11 The Regent Of The University Of Michigan Polarized gas delivery system/method
FR2768568B1 (fr) * 1997-09-17 2000-02-25 Centre Nat Rech Scient Procede et equipement pour la preparation d'un gaz d'helium hyperpolarise a forte pression, application dudit procede
DE19742543C2 (de) * 1997-09-26 1999-09-23 Otten Ernst Wilhelm Verfahren und Vorrichtung zur Bestimmung des Polarisationsgrades kernspinpolarisierter Gase, insbesondere des Heliumisotops ·3·He sowie ·1··2··9·Xe
BR9813492A (pt) * 1997-12-12 2000-11-21 Magnetic Imaging Technologies Processos de extensão da vida útil de polarização de um produto de gás nobre polarizado, de congelamento e de degelo de gás nobre polarizado congelado coletado e de realização de etapas de degelo e/ou conversão, acumulador criogênico para coletar os gases nobres polarizados congelados, camisa de aquecimento, e, produtos de gás 129xe polarizado farmacêutico, de gás nobre 129xe hiperpolarizado farmacológico e de gás nobre polarizado
US6079213A (en) * 1997-12-12 2000-06-27 Magnetic Imaging Technologies Incorporated Methods of collecting, thawing, and extending the useful life of polarized gases and associated accumulators and heating jackets
WO1999047940A1 (fr) * 1998-03-18 1999-09-23 Magnetic Imaging Technologies Incorporated PROCEDE D'IMAGERIE PAR RESONANCE MAGNETIQUE DU SYSTEME CARDIOVASCULAIRE PULMONAIRE ET CARDIAQUE ET D'EVALUATION DU DEBIT SANGUIN AU MOYEN DE 129Xe POLARISE DISSOUS
EP1090250A1 (fr) * 1998-06-17 2001-04-11 Medi-Physics, Inc. Dispositifs de transport et procede de transport associe
US6423387B1 (en) * 1998-06-17 2002-07-23 Medi-Physics, Inc. Resilient containers for hyperpolarized gases and associated methods
US6286319B1 (en) * 1998-09-30 2001-09-11 Medi-Physics, Inc. Meted hyperpolarized noble gas dispensing methods and associated devices
US6237363B1 (en) * 1998-09-30 2001-05-29 Medi-Physics, Inc. Hyperpolarized noble gas extraction methods masking methods and associated transport containers
US6284222B1 (en) * 1998-11-03 2001-09-04 Medi--Physics, Inc. Hyperpolarized helium-3 microbubble gas entrapment methods
US6648130B1 (en) * 1999-08-11 2003-11-18 Medi-Physics, Inc. Hyperpolarized gas transport and storage devices and associated transport and storage methods using permanent magnets
US6630126B2 (en) * 2000-03-13 2003-10-07 Medi-Physics, Inc. Diagnostic procedures using direct injection of gaseous hyperpolarized 129Xe and associated systems and products
EP1438600A2 (fr) * 2001-10-22 2004-07-21 Medi-Physics, Inc. Modules de pompage optique, systemes de melange et de diffusion de gaz polarise, systemes automatiques de diffusion de gaz polarise, dispositifs et procedes connexes
JP3998243B2 (ja) * 2003-01-10 2007-10-24 東横化学株式会社 核スピン偏極キセノンガスの製造方法及び製造装置
EP1588178B1 (fr) * 2003-01-17 2011-10-12 Medi-Physics Inc. Procede de production d'un gaz hyperpolarise par pompage optique
CN1739035A (zh) * 2003-01-17 2006-02-22 医疗物理有限公司 用于传送超极化的气体的泵系统和方法
US6907740B2 (en) * 2003-07-23 2005-06-21 Advanced Technology Materials, Inc. Gas charging system for fill of gas storage and dispensing vessels
DE102004002639A1 (de) * 2004-01-19 2005-09-15 Forschungszentrum Jülich GmbH Verfahren zur Anreicherung von hyperpolarisierten Atomkernen und Vorrichtung zur Durchführung des Verfahrens
WO2007038626A2 (fr) * 2005-09-28 2007-04-05 President And Fellows Of Harvard College Materiaux solides hyperpolarises avec temps prolonges de relaxation spin utilises en tant qu'agents imageurs en imagerie par resonance magnetique
US7576538B2 (en) * 2006-03-14 2009-08-18 Thomas Meersmann Nuclear electric quadrupolar properties of hyperpolarized gases to probe surfaces and interfaces
US8405022B2 (en) * 2006-09-20 2013-03-26 University Of New Hampshire Thermal management technology for polarizing xenon
JP4817317B2 (ja) * 2006-11-24 2011-11-16 独立行政法人産業技術総合研究所 核スピン偏極希ガスの製造装置と核磁気共鳴分光装置並びに核磁気共鳴イメージング装置
WO2010013743A1 (fr) * 2008-08-01 2010-02-04 国立大学法人大阪大学 Procédé de concentration de xénon gazeux polarisé, dispositif d'alimentation pour la fabrication de xénon gazeux polarisé, et système d'irm
US8773130B2 (en) * 2009-04-01 2014-07-08 The University Of North Carolina At Chapel Hill Device for particulate NMR samples in a fluid and related methods

Also Published As

Publication number Publication date
US20120160710A1 (en) 2012-06-28
WO2009143368A3 (fr) 2010-02-25

Similar Documents

Publication Publication Date Title
Anger et al. Gas-phase spin relaxation of Xe 129
US5612103A (en) Coatings for production of hyperpolarized noble gases
US7576538B2 (en) Nuclear electric quadrupolar properties of hyperpolarized gases to probe surfaces and interfaces
Moudrakovski et al. Chemical shift imaging with continuously flowing hyperpolarized xenon for the characterization of materials
Kuzma et al. Fast nuclear spin relaxation in hyperpolarized solid 129 Xe
Wong et al. A system for low field imaging of laser-polarized noble gas
Brunner Enhancement of surface and biological magnetic resonance using laser‐polarized noble gases
Krjukov et al. Brute force polarization of 129Xe
Cleveland et al. Exploring hyperpolarized Kr83 by remotely detected NMR relaxometry
US20120160710A1 (en) Non-cryogenic storage cell for hyperpolarized 129xe
US20070156046A1 (en) Method of enriching hyperpolarized atom nuclei and an apparatus for implementing the method
Berry-Pusey et al. Nuclear spin relaxation of Xe 129 due to persistent xenon dimers
Leawoods et al. Polarization transfer using hyperpolarized, supercritical xenon
Shao et al. Low readout field magnetic resonance imaging of hyperpolarized xenon and water in a single system
Patton et al. Chemical shift of hyperpolarized 129 Xe dissolved in liquid nitrogen
Kelley et al. Background‐Free Detection of Spin‐Exchange Dynamics at Ultra‐Low Magnetic Field
Suchanek et al. Hyperpolarized^ 3He gas production by metastability exchange optical pumping for magnetic resonance imaging
Collier et al. Metastability exchange optical pumping low field polarizer for lung magnetic resonance imaging.
AU695121C (en) Coatings for production of hyperpolarized noble gases
Stupic et al. all of the data discussed in this chapter. Galina E. Pavlovskaya designed and built the" Kr
Ishikawa et al. Magnetic resonance imaging of spin-polarization transfer of polarized Xe atoms dissolving into ethanol
Goodson et al. NMR and MRI of laser-polarized noble gases in molecules, materials, and medicine
Morgan Relaxation of solid hyperpolarized 129Xe
Pravdivtsev et al. Continuous Radio Amplification by Stimulated Emission using Parahydrogen Induced Polarization (PHIP-RASER) at 14 Tesla
KRYPTON et al. and processed the image data. Zackary I. Cleveland produced the hp" Kr, designed the

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 09751596

Country of ref document: EP

Kind code of ref document: A2

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 09751596

Country of ref document: EP

Kind code of ref document: A2