Metastabilityexchange optical pumping meop is our method of choice to polarize the 3he atoms. Metastability exchange optical pumping of 3he at 1. Meop stands for metastability exchange optical pumping. Metastability exchange optical pumping of helium3 at high. After being hyperpolarized using the technique of metastability exchange optical pumping meop, 3 he can be used as a contrast agent for lung magnetic resonance imaging mri. Pdf metastability exchange optical pumping low field polarizer for. Fundamentals of metastability exchange optical pumping in helium and find more. This process is able to polarize 3 he nuclei in the ground state with optically pumped 3 he nuclei in the metastable state. In a recent paper, we demonstrated that operating at 1. Metastable xenon is created by electrodeless rf discharge.
Accelerators, spectrometers, detectors and associated equipment 764 2014. By varying the discharge intensity in the cell, the density of metastable state atoms and. Advanced collisional radiative model for helium plasma. Systematic studies of the metastability exchange optical pumping meop process in 3he gas at high magnetic fields 0. Comparative study of laserinduced metastabilityexchange optical pumping of 3 he atoms through 2 3 s 3 p j transition at 389 nm with 2 3 s 12 3 p j transition at 1083 nm. Pdf hyperpolarized he3 gas production by metastability. Metastability exchange optical pumping listed as meop. Nuclear instruments and methods in physics research section a. Dense samples 10100barcm of nuclear spin polarized he3 are utilized in high energy physics, neutron scattering, atomic physics, and magnetic resonance imaging. The nuclear polarization process through optical pumping op between the radiative state 23p and the metastable state 23s in he, as well as the metastability exchange me, have been widely studied since the original model developed by nacher and leduc j. Advances in metastability exchange optical pumping meop of 3he at high laser powers, with its various applications, but also at high gas pressures p3 and high magnetic field strengths b, have provided strong motivation for revisiting the understanding and for investigating the limitations of this powerful technique. How is metastability exchange optical pumping abbreviated.
In this work, the complete update of a low field polarizer dedicated to small animal lungs imaging is presented. Scilit article enhanced polarization of low pressure 3he. A highfield 3he metastability exchange optical pumping. Apr 20, 2005 dense samples 10100barcm of nuclear spin polarized he3 are utilized in high energy physics, neutron scattering, atomic physics, and magnetic resonance imaging. Metastability exchange optical pumping meop of 3he in. Polarized helium3 is used as a contrast agent for lungs magnetic resonance imaging that has recently reached the preclinical applications. We developed a metastability exchange optical pumping technique for metastable triplet helium 3 he atoms utilizing the 2 3 s 3 p j transition at 389 nm with radiation generated by a frequencydoubled cw ti. The main idea of optical pumping by exchange of metastability was found in early 60s. Effects of weak hyperfine decoupling on metastability. The rf discharge used for optical pumping, op, promotes of a small fraction of the. The 23s23p transition at 1083 nm is used for optical pumping and for detection of the laserinduced orientation of 3he atoms in the rf discharge plasma. In comparison to metastabilityexchange optical pumping meop 911, seop is rela. The nuclear polarization of 3he can be discerned from its electron polarization, measured via the circular polarization of 668 nm discharge light from an rf excitation. Metastabilityexchange optical pumping how is metastability.
Polarization of 3he by spin exchange with optically pumped. The atoms are polarized via metastability exchange optical pumping in the helmholtz coil and are in diffusive contact via a glass tube with a second test cell in the solenoid. Through careful manipulation of the rf discharge parameters, polarizations above 80% were attained at 2, 3 and 4t, with 89% being reached at 3t with a 664s relaxation time. Metastability exchange optical pumping low field polarizer. In contrast to metastability exchange, collisional spin exchange with optically pumped alkali metal vapors can take place at high pressures without sacrificing polarization, but with much slower spinexchange rates. Metastability exchange optical pumping of 3he gas up to. However, the plasma discharge processes, which include all the. Metastability exchange optical pumping of 3 he at high. Sapphire laser and compared the results with our results obtained utilizing the 2 3 s 12 3 p j transition at 1083 nm with a diode laser. We report high steadystate nuclear polarization of 1 torr 3he gas nuclei via metastability exchange optical pumping at magnetic fields above 2 t. The impact of experimental parameters such as laser power, beam profile, and shape of the pumping cell is evaluated. Fundamentals of metastability exchange optical pumping in. Liquid crystal polarimetry for metastability exchange optical.
Metastability exchange optical pumping can rapidly produce high he3 polarizations. At low magnetic field, metastability exchange optical pumping of helium3 is known to provide high nuclear polarizations for pressures. The efficiency of the metastability exchange optical pumping meop performed at elevated 3he gas pressures in high magnetic field was improved by modifying the spatial profile of the pumping. Meop is defined as metastabilityexchange optical pumping somewhat frequently. Production rate was raised by a factor of 10 to 45 sccmin thanks to the implementation of a new 10 w laser and a new design of a peristaltic compressor, easier to handle. Metastabilityexchange optical pumping listed as meop. We developed a metastabilityexchange optical pumping technique for metastable triplet helium 3 he atoms utilizing the 2 3 s 3 p j transition at 389 nm with radiation generated by a frequencydoubled cw ti. Fundamentals of metastability exchange optical pumping in helium. Meop is usually performed at low magnetic field 1 mt and low pressure 1 mbar, which results in a low magnetization production rate. An accurate optical technique for measuring the nuclear polarisation of 3 he gas c talbot et alfundamentals of metastability exchange optical pumping in helium m batz et al optical measurement of 3he nuclear polarization for metastable exchange optical pumping studies at high magnetic field z. For this purpose, we present systematic experimental and theoretical studies.
The atomic polarization of metastable xe is on the order of 10%. He metastability exchange optical pumping polarizer. We perform metastability exchange optical pumping of helium3 in a strong magnetic field of 1. Pdf metastability exchange optical pumping of helium3 at. Apr 11, 2020 we report high steadystate nuclear polarization of 1 torr 3he gas nuclei via metastability exchange optical pumping at magnetic fields above 2 t.
Read comparative study of laserinduced metastabilityexchange optical pumping of 3 he atoms through 2 3 s 1 3 3 p j transition at 389 nm with 2 3 s 1 2 3 p j transition at 1083 nm, optical engineering on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. The efficiencies of two ytterbium yb fiber lasers for metastability exchange optical pumping are compared with that of an arclamppumped neodymiumdoped lanthanum magnesium hexaluminate laser. Comparative study of laserinduced metastabilityexchange. It produces 3he gas polarized up to 40% in a 6 h decay time storage cell. Pdf a portable 3he gas polarizer based on metastability exchange optical pumping is described. The 3he atoms will be polarized using the technique of metastabilityexchange optical pumping meop, and will then be owed into the newly commissioned electron beam ion source ebis.
Metastability exchange optical pumping of 3he gas up. The conventional application of polarized 3he as a spin. A compact compressor for application of metastability. In this technique, a weak rf discharge excites atoms into the metastable 23s state, where they are pumped to the 23p states by 1083 nm circularly polarized laser light tuned to either the c8 or c9 transition fig. Spinexchange optical pumping is a two stage process which begins.
In this work, the complete update of a low field polarizer dedicated to. Hyperpolarized gas magnetic resonance imaging has recently emerged as a method to image lungs, sinuses, and the brain. An accurate optical technique for measuring the nuclear polarisation of 3 he gas c talbot et alfundamentals of metastability exchange optical pumping in helium m batz et aloptical measurement of 3he nuclear polarization for metastable exchange optical pumping studies at. The introduction of highly polarized 3 he gas into brookhavens electron beam ion source would enable a new, polarized 3 he ion source for use at the relativistic heavy ion collider and a future electronion collider facility. The best lung images to date have been produced using hyperpolarized 3 he, which is produced by either spin. How is metastabilityexchange optical pumping abbreviated. Systematic studies of the metastability exchange optical pumping meop process in 3 he gas at high magnetic fields 0.
We detail the design and operation of a compact, discharge light polarimeter for metastability exchange optical pumping of 3he gas near 1 torr under a low magnetic field. A energy transitions involved in metastable optical pumping of helium. In situ polarized 3he system for the magnetism reflectometer. Two methods are widely used to produce spinpolarized 3he, seop and metastability exchange optical pumping meop 14,15. This apparatus measures the circular polarization of. Literature values for the key spinexchange and spinloss rates are suf. Metastability exchange optical pumping meop of 3he in situ abstract. Metastability exchange optical pumping meop of he in situ mit. Liquid crystal polarimetry for metastability exchange.
After being hyperpolarized using the technique of metastability exchange optical pumping meop, 3he can be used as a contrast agent for lung magnetic resonance imaging mri. Polarized he3 gas compression system using metastability. Advances in metastability exchange optical pumping meop at high. Metastability exchange optical pumping low field polarizer for lung magnetic resonance imaging. At low magnetic field, metastability exchange optical pumping of helium3 is known to provide high nuclear polarizations for pressures around 1 mbar. Spinexchange optical pumping seop of 3he 1,2 is an important method in several areas of physics, including neutron spin. The method involves optical pumping op on the 2 3s2 p transition at 1083 nm a strongly imbalanced distribution of atoms among the hyper. T uropean physical ournal metastability exchange optical. Metastability exchange optical pumping of 3he gas up to hundreds of millibars at 4.
We describe a polarized he3 gas compressor system which accepts 0. Meop stands for metastabilityexchange optical pumping. Sep 01, 2010 comparative study of laserinduced metastability exchange optical pumping of 3 he atoms through 2 3 s 3 p j transition at 389 nm with 2 3 s 12 3 p j transition at 1083 nm. Optical pumping is performed in standard conditions at low pressure 1 mbar and low magnetic field 1 gauss. Openings op polarised helium, quantum fluids and solids. We report high steadystate nuclear polarization of 1 torr 3 he gas nuclei via metastability exchange optical pumping at magnetic fields above 2 t. Meop metastabilityexchange optical pumping acronymfinder. Spinexchange optical pumping of 3he with rbk mixtures and. Polarization of metastable 129xe tian xia, steven morgan. On the other hand, helium3 is polarized with a laser by the metastability exchange without using an alkali metal.
Polarization of 3he by spin exchange with optically pumped rb. Advances in metastability exchange optical pumping meop at high laser powers, but also at high gas pressures and high magnetic field strengths, has provided strong motivation for revisiting the understanding of the limitations of this powerful technique. The efficiencies of two ytterbium yb fiber lasers for metastabilityexchange optical pumping are compared with that of an arclamppumped neodymiumdoped lanthanum magnesium hexaluminate laser. Liquid crystal polarimetry for metastability exchange optical pumping of superscript 3he. An rf discharge placed across a lowpressure sample e. Metastability exchange optical pumping meop is experimentally investigated in 3 he at 4. The 2 3 s2 3 p transition at 1083 nm is used for optical pumping and for detection of the laserinduced orientation of 3 he atoms in the rf discharge plasma. Pdf comparison of metastabilityexchange optical pumping.
An extensive improvement of our low field polarizer is described. Metastability exchange optical pumping of 3 he gas up to. Metastability exchange optical pumping in 3he gas up to 30 mt. Development of a polarized helium3 ion source for rhic. Sep 01, 2010 read comparative study of laserinduced metastability exchange optical pumping of 3 he atoms through 2 3 s 1 3 3 p j transition at 389 nm with 2 3 s 1 2 3 p j transition at 1083 nm, optical engineering on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. May 28, 20 after being hyperpolarized using the technique of metastability exchange optical pumping meop, 3 he can be used as a contrast agent for lung magnetic resonance imaging mri. Demonstration of a compact compressor for application of. A compact compressor for application of metastabilityexchange optical pumping of 3he to human lung imaging t. Pdf high nuclear polarization of 3he at low and high. Introduction principle of optical pumping proton images helium. Meop only involves 3 he nuclei at room temperature and at low pressure. One method to hyperpolarize 3he is the metastability exchange optical pumping meop.
Optical monitoring of the 3e emission spectrum and polarization are used to aid in the efficient production of highly nonequilibrium nuclearspin polarized hyperpolarized 3e. Meop is defined as metastability exchange optical pumping somewhat frequently. Metastability exchange optical pumping meop of 3he in situ. Pdf metastability exchange optical pumping of 3 he at. High nuclear polarization of 3 he at low and high pressure by. At low magnetic field, metastability exchange optical pumping of helium 3 is known to provide high nuclear polarizations for pressures. Metastability exchange optical pumping meop is experimentally investigated in 3he at 4. I metastability exchange optical pumping meop of 3he in situ abstract. We discuss the design of the source, and the status of its. Scheme of metastability exchange optical pumping see text.
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