Tools to construct a model for sources of radioactive backgrounds in a low radioactivity dertector system
A common problem in detector systems is estimating the background. For radiation detectors, often the background is dominated by a few sources, and this is relatively easy to determine. However, for ultra-low background radiation detectors, even small components can have a large effect. Keeping track of all these components, and multiple radioactivity specifications for each one can become an accounting nightmare.
This module provides a suite of classes that can be used to aid in this task. At it's base, a background model is a hierarchy of components (screws, circuitboards, flanges, cryostats, wires), each with a list of specifications (bulk U238 rates, dust on surfaces), and normalized by an efficiency factor, usually derived from simulations (not part of this module).
A component usually represents a physical object: a screw, wire, bucket, etc. Components have a name and optional description and comment, and store related physical quanitities needed to normalize radioactive emissions:
- material
- mass
- volume
- surface_in (inner surface area, for things like cans)
- surface_out (outer area for things like cans)
- can also just be surface
- additional physical quanities can be specified by the 'physical_quantities' parameter.
Components will also contain a list of CompSpecs that define the radioactivity levels.
Additional information like part numbers, vendors, dates received, links to tracking information, etc, can be provided in the 'extrainfo' parameter.
An assembly has a name, optional desription and comment, and contains a list of sub-components and/or sub-assemblies. Each subcomponetn can also be given a weight, typically used for multiple part numbers (e.g. a flange assembly may have 20 bolts as subcomponents.) Or, if a 'wire' component is specified given with a mass of 1 g/meter, the weight given might be 30 meters.
in progress