Pileup mod - Pseudo function for correcting pileup

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(New page: ==Pileup Correction Component== ===Introduction=== pileup_mod attempts to correct for photons which lose energy in the detector at the same time (within 1 microsecond of each other). Photo...)
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Revision as of 20:16, 9 July 2009

Contents

Pileup Correction Component

Introduction

pileup_mod attempts to correct for photons which lose energy in the detector at the same time (within 1 microsecond of each other). Photons that arrive within the 1 µs are counted as a single event with the energy of the photons summed. During high countrate time intervals of a flare this detector effect can distort the spectrum. This fit component attempts to fit pileup effects during these intervals, this allows a more accurate measure of physical parameters such as the Emission Measure and Temperature.

Parameters

pileup_mod - always returns a value of 0. Parameters are varied during fit and used in apply_drm method to add pileup effects to model on the fly.

Synopsis

Pileup causes a distortion of the RHESSI spectrum during high countrate time intervals of an event. RHESSI Spectra have a low energy peak. During high countrate time intervals it becomes likely that any two photons losing energy in the detector within 1µs will have the energy of a photon around the peak of the spectrum. This leads to a shoulder in the spectrum at around twice the value (in keV) of the low energy peak. There is some spread to the shoulder just as there is spread to the peak of spectrum due to smearing of counts during binning and other statistical variations. Below is a typical spectrum showing pileup.


Fitting with pileup_mod

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