@S05487-1@ of radiation in a generally backward direction. In the @A00470@ of @R05092@, it applies to the @S05487-2@ of radiation into the @R05054@ from any material except the sample and the detector. In @L03525@, it is said to occur when the @S05488@, \(\theta \), is \(180^{\,\unicode{x26ac}}\). Conversely, forward scattering occurs when \(\theta \) is \(0^{\,\unicode{x26ac}}\).