Envelope task #1438: === Physics ===
No impact of abundance optional argument in ParticleLayout addParticle method for single particle
|Status:||Rejected||Start date:||11 Nov 2016|
The class ParticleLayout has the addParticle method, which takes the particle abundance as optional second parameter.
It is expected that this defines the relative abundance of these particles in the given layer and therefore should directly influence the intensity of that form factor component.
When varying the parameter from 1 to 1e-100 there is no change observed in the simulated intensity. Only setting it to exactly 0 will remove that scattering component. (See attached images for example of rough layer system with 2D Para Crystal model.)
This is a critical issue, as it is a necessary parameter when defining systems with more than one type of particles.
#1 Updated by herck almost 3 years ago
- Tracker changed from Bug to Feature
- Subject changed from No impact of abundance optional argument in ParticleLayout addParticle method to No impact of abundance optional argument in ParticleLayout addParticle method for single particle
- Status changed from New to Backlog
- Priority changed from High to Normal
The abundance parameter passed in the addParticle method denotes a relative abundance. The relative abundances of the different particles inside a single ParticeLayout are internally normalized to one during calculations. For a single particle, this implies the described behavior. The parameter that truly manipulates the number density of particles in a layout, is set by ParticleLayout::setTotalParticleSurfaceDensity(double), in number of particles per square nm.
While the described behavior is intentional, I understand this may incur some confusion.
Can you please add comments as to how you would prefer to see this from the API side?