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We describe an alkali-metal magnetometer for detection of weak magnetic fields in the radio-frequency (rf) range. High sensitivity is achieved by tuning the Zeeman resonance of alkali atoms to the rf frequency and partially suppressing spin-exchange collisions in the alkali-metal vapor. We demonstrate magnetic field sensitivity of 2 fT/Hz(1/2) at a(More)
Using a new method of xenon laser-polarization that permits the generation of liter quantities of hyperpolarized 129Xe gas, the first 129Xe imaging results from the human chest and the first 129Xe spectroscopy results from the human chest and head have been obtained. With polarization levels of approximately 2%, cross-sectional images of the lung gas-spaces(More)
A radio-frequency tunable atomic magnetometer is developed for detection of nuclear quadrupole resonance ͑NQR͒ from room temperature solids. It has a field sensitivity 0.24 fT/ Hz 1/2 at the 423 kHz 14 N NQR frequency of ammonium nitrate. A potential application of the magnetometer is detection of nitrogen-containing explosives which is difficult with(More)
NQR detection of materials, such as TNT, is hindered by the low signal-to-noise ratio at low NQR frequencies. Sweeping small (0-26 mT) magnetic fields to shift the (1)H NMR frequency relative to the (14)N NQR frequencies can provide a significant increase of the (14)N NQR signal-to-noise ratio. Three effects of (1)H-(14)N level crossing are demonstrated in(More)
Nitrogen is prevalent in many materials, both naturally occurring and man-made. In particular, it is found in many explosives and other contraband materials. One technique for the detection of such materials in the field is the use of the magnetic resonance signal from the nearly 100% abundant, spin-1, 14N nuclei. Some of the difficulties with such(More)
We report the first detection of a spin echo after excitation of a powder sample by a single pulse at the resonance frequency during nuclear quadrupole resonance (NQR). These echoes can occur in samples that have an inhomogeneously broadened line, in this case due to the distribution of electric field gradients. The echoes are easily detectable when the(More)
Using double-resonance conditions, in which the Larmor frequency of a spin-1/2 nucleus is matched to one of the nuclear quadrupole resonance frequencies of a spin-1 nucleus, the authors demonstrate increased cross relaxation between the two nuclear spin species. They calculate the cross-relaxation rate using the motionally averaged heterogeneous dipole(More)
We demonstrate the creation of two novel double-resonance conditions between spin-1 and spin-1/2 nuclei in a crystalline solid. Using a magnetic field oscillating at the spin-1/2 Larmor frequency, the nuclear quadrupole resonance (NQR) frequency is matched to the Rabi or Rabi plus Larmor frequency, as opposed to the Larmor frequency as is conventionally(More)
We investigate theoretically and experimentally the role of broadening due to heteronuclear dipolar coupling in spin-1 nuclear quadrupole resonance pulsed spin locking. We find the experimental conditions where heteronuclear dipolar coupling is refocused by a standard multipulse sequence. This experimental condition allows us to extend our previously(More)
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