Smaluk, V.V. JACoW Geneva, Switzerland 978-3-95450-192-2 10.18429/JACoW-IBIC2017-MO3AB2 English 28-31 MO3AB2 ion impedance wakefield simulation damping Contribution to a conference proceedings 2018 2018-03 https://doi.org/10.18429/JACoW-IBIC2017-MO3AB2 http://jacow.org/ibic2017/papers/mo3ab2.pdf Characterization of a vacuum chamber impedance is necessary to estimate stability conditions of a particle beam motion, to find a limit of the beam intensity and characteristic times of single-bunch and multi-bunch instabilities. For a new accelerator project, minimization of the impedance is now the mandatory requirement for the vacuum chamber design. For an accelerator in operation, the impedance can be measured experimentally using various beam-based techniques. The beam-impedance interaction manifests itself in measurable beam parameters, such as betatron tunes, closed orbit, growth rates of instabilities, bunch length and synchronous phase. The beam-based techniques developed for measurement of the longitudinal and transverse impedance are discussed, including theoretical basics and experimental results.