1. A phenomenon which occurs when two objects naturally vibrate at the same frequency.

An example can be demonstrated when two tuning forks that are tuned to the same frequency are held close to each other and one is struck, then the other one will begin to vibrate.

Acoustic resonances exist in the human body, in which the structures of the head and throat give the voice its tone.

2. A quality which makes something personally meaningful or important to other people: "The story that the speaker presented had a great deal of resonance with the audience."

1. A source of multiple charged heavy ions which uses microwave power to increase electron energy to extremely high levels in two magnetic-mirror confinement chambers connected in a series.
2. An electrode supplying current of charged heavy ions that uses microwave power to heat electrons to energies of tens of kilovolts in two magnetic mirror confinement chambers in a series.

Ions formed in the first chamber drift into the second chamber, where they become charged.

1. A spectroscopic technique in which a sample is irradiated with a range of nuclear resonance frequencies while electron spin resonance absorption is observed at a single frequency.
2. A type of electron paramagnetic resonance spectroscopy permitting greatly enhanced resolution, in which a material is simultaneously irradiated at one of its frequencies and by a second oscillatory field during which its frequency is swept over the range of nuclear frequencies.

1. A resonant absorption of electromagnetic radiation by a paramagnetic substance, having unpaired electrons, when the energy levels are split by the application of a strong magnetic field.
2. Magnetic resonance arising from the magnetic moment of unpaired electrons in a paramagnetic substance or in a paramagnetic center in a diamagnetic substance (a group of substances which in a magnetic field become magnetic in an opposite direction to that of iron or relating to a substance that is repelled by a magnet).

A spectrometer or an instrument that produces a spectrum; especially, one in which wavelength, energy, intensity, etc., can be measured based on electron paramagnetic resonance.

1. A mass spectrometer in which the mass distribution of orbiting ions within a magnetic field is detected by bringing ion frequencies sequentially into resonance with applied radio frequencies.
2. A device for detecting and measuring the mass distribution of ions orbiting in an applied magnetic field, either by applying a constant radio-frequency signal and varying the magnetic field to bring ion frequencies equal to the applied radio frequency sequentially into resonance, or by rapidly varying the radio frequency and applying Fourier transform techniques (an operation that transforms one complex-valued function of a real variable into another one).

Fourier transform techniques as used in electronics, control systems engineering, and statistics, is a term used to describe the analysis of mathematical functions or signals with respect to frequency, rather than time.

1. A type of diagnostic radiography using electromagnetic energy.

Certain atomic nuclei with an odd number of neutrons, protons, or both are subjected to a radio-frequency pulse, causing them to absorb and release energy.

2. A non-invasive method of imaging the body and its organs; as well as, studying tissue metabolism.

More details about MRI

The body is placed in a magnetic field which causes certain atomic nuclei to align in the direction of the field. Pulses of radio-frequency radiation are then applied; interpretation of the frequencies absorbed and re-emitted allows an image in any body plane to be built up.

Different tissues; for example, fat and water, can be separately identified and, if the resonance signal for the fat is suppressed, then only the signal from any abnormalities in the fat can be identified.

Many diseases result in a rise in the water content of tissues; so, MRI, or magnetic resonance imaging, is a valuable test for identifying certain diseases.