Ammonia as a polarized solid target material—a review

Meyer, W.

doi:10.1016/j.nima.2004.03.145

Cited by 23 publications

(13 citation statements)

References 23 publications

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“…(While the preparation of pseudo-pure initial states allows high-temperature NMR quantum computing [ 9 ], the readout signal becomes exponentially small as the number of qubits goes up [ 10 ]). Methods of achieving nuclear polarization are also useful in other contexts, including NMR [ 11 ] and high-energy physics [ 12 ]. Four microwave-induced dynamic nuclear polarization (DNP) effects have been demonstrated in the past: The Overhauser effect (OE) 13 , the solid effect (SE), thermal mixing (TM) and the cross effect (CE).…”

mentioning

confidence: 99%

Efficient Dynamic Nuclear Polarization at High Magnetic Fields

et al. 2007

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By applying a new technique for dynamic nuclear polarization involving simultaneous excitation of electronic and nuclear transitions, we have enhanced the nuclear polarization of the nitrogen nuclei in 15 N@C 60 by a factor of 10 3 at a fixed temperature of 3 K and a magnetic field of 8.6 T, more than twice the maximum enhancement reported to date. This methodology will allow the initialization of the nuclear qubit in schemes exploiting N@C 60 molecules as components of a quantum information processing device.The incarceration of atomic nitrogen in a C 60 cage leads to a species (known as N@C 60 ) with remarkable properties: The nitrogen occupies a high-symmetry site at the center of the cage and retains its atomic configuration, and the cage offers protection of the nitrogen electron paramagnetic moment from interactions with the environment . T 2 is of the order of 10 4 times longer than the time taken to manipulate the electron spin state by pulsed electron spin resonance (ESR), and this has led to speculation that it may be a useful component in an electron-spin-based quantum computer[ 4 , 5 , 6 , 7 , 8 ]. The nuclear spin of the incarcerated N atom exhibits even longer lifetimes, and it too can in principle be used to store quantum information. However, before the nuclei can be exploited as qubits, a method of polarizing them would be required, and this method should work at temperatures that are high on the scale of the nuclear Zeeman energy. (While the preparation of pseudo-pure initial states allows high-temperature NMR quantum computing

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confidence: 99%

Efficient Dynamic Nuclear Polarization at High Magnetic Fields

et al. 2007

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“…For 14 NH 3 EPR line width of 120 MHz in 10 GHz X-band spectrometer with 350 mT field has been observed [4]. Lower lattice temperature T L helps but is not always easy to achieve due to the heat coming from pumping of the electron spins with microwaves.…”

Section: Proton Polarizationmentioning

confidence: 98%

“…In frozen spin mode the dilution cryostat can keep the target material Typical density of paramagnetic centers in solid polarized target materials is about 10 −4 -10 −3 free electrons/nucleus. In case of ammonia these areṄ H 2 radicals [4]. They have been created in 20 MeV electron beam at the Bonn linac at 80 -90 K irradiation temperatures [2].…”

Section: Target Systemmentioning

confidence: 99%

Polarization of the large COMPASS¹⁴NH₃target

Koivuniemi

Doshita

Gautheron

et al. 2009

J. Phys.: Conf. Ser.

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“…Paramagnetic centers are necessary to transfer the high electron polarization obtained at a high magnetic field (> 2.5 T) and at low temperatures (< 1 K) to the nuclei. There are two generally applicable methods to induce paramagnetic centers into the target materials, (1) chemically doping (2) to irradiate the material such as ammonia, deuterated ammonia or deuterated lithium by ionizing radiation, e.g. by an intense electron beam [2,3,4].…”

Section: Introductionmentioning

confidence: 99%

“…There are two generally applicable methods to induce paramagnetic centers into the target materials, (1) chemically doping (2) to irradiate the material such as ammonia, deuterated ammonia or deuterated lithium by ionizing radiation, e.g. by an intense electron beam [2,3,4]. For an effective DNP process, a number of 2 × 10 19 spins/g were shown to be most suitable.…”

Section: Introductionmentioning

confidence: 99%

DNP measurements of irradiated deuterated polyethylene

Wang¹

2016

Proceedings of XVIth International Workshop in Polarized Sources, Targets, and Polarimetry — PoS(PSTP2015)

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Deuterated polyethylene samples have been prepared as polarizable target material. The paramagnetic centers necessary for the dynamic nuclear polarization process have been created by irradiation with electrons. The paramagnetic resonance from the induced centers into the samples has been studied in a conventional X-band EPR spectrometer operating at 9.35 GHz and at liquid nitrogen temperature. In a fully deuterated polyethylene sample more than 30% deuteron polarization has been achieved at dilution refrigerator temperature and 2.5 T.

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Ammonia as a polarized solid target material—a review

Cited by 23 publications

References 23 publications

Efficient Dynamic Nuclear Polarization at High Magnetic Fields

Efficient Dynamic Nuclear Polarization at High Magnetic Fields

Polarization of the large COMPASS¹⁴NH₃target

DNP measurements of irradiated deuterated polyethylene

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Ammonia as a polarized solid target material—a review

Cited by 23 publications

References 23 publications

Efficient Dynamic Nuclear Polarization at High Magnetic Fields

Efficient Dynamic Nuclear Polarization at High Magnetic Fields

Polarization of the large COMPASS14NH3target

DNP measurements of irradiated deuterated polyethylene

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Polarization of the large COMPASS¹⁴NH₃target