Multi-shape pulse pile-up correction: The MCPPU code

• Pulse pile-up (PPU) is a common distortion in radiation detection.
• MCPPU is a Monte Carlo code to perform post-processing PPU correction.
• MCPPU evaluates automatically the dead time to use in the pile-up recovery.
• The measured pulse shape can be introduced as a normalized discrete distribution.
• MCPPU is compatible with detectors using electronic rejection circuitry.

In spectroscopic measurements with high counting rate, pulse pile-up (PPU) is a common distortion of the spectrum. It is fully ascribable to the pulse handling circuitry of the detector and it is not comprised in the detector response function which is well explained by a purely physical model. Since PPU occurs after the transport inside the detector, this is the first correction to perform in case of spectrum unfolding. Many producers include electronic rejection circuits to limit the appearance of PPU, but it is never suppressed completely. Therefore, it is always necessary to correct PPU distortions after the measurement. In the present work, it is described the post-processing tool MCPPU (Monte Carlo Pulse Pile-Up), based on the MC algorithm developed by Guo et al., 2004 and Guo et al., 2005. MCPPU automatically determines the dead time of the counting system and corrects for PPU effects even in the presence of electronic suppression. The capability of allowing a user defined pulse shape makes the code suitable to be used with any kind of detector. The features of MCPPU are illustrated with some examples.