Why ebtelplusplus?#
For various historical reasons, there are multiple software implementations of the EBTEL model.
There are currently three maintained implementations of the model as described below.
Hereafter, “EBTEL” refers to the model generally while each software implementation is given
its own unique name (e.g. ebtelplusplus).
This page briefly explains the differences between each implementation and the advantages of
the ebtelplusplus implementation.
The table below summarizes the comparison of the different EBTEL software implementations and the different features provided by each.
Feature |
Citation |
|
||
|---|---|---|---|---|
Decouple electrons and ions |
Barnes et al. [BCB16] |
|||
Adaptive time step |
Barnes et al. [BCB16] |
|||
Area expansion |
Cargill et al. [CBKB22] |
|||
Supersonic flows |
Rajhans et al. [RTB+22] |
|||
Time-variable abundances |
Reep et al. [RUBC24] |
EBTEL-IDL#
The original software implementation of EBTEL was in the Interactive Data Language (IDL) and
was based off of the model presented in Klimchuk et al. [KPC08].
Subsequent improvements in Cargill et al. [CBK12b] were made to give better
agreement with spatially-resolved hydrodynamic models.
These improvements were also implemented in IDL.
This version is sometimes referred to as “EBTEL2”.
Cargill et al. [CBKB22] extended the EBTEL model to include effects due to cross-sectional
area expansion and implemented this in IDL as well.
The IDL software implementation which includes all of these features is referred to as EBTEL-IDL.
EBTEL3-IDL#
Rajhans et al. [RTB+22] built upon the model of Cargill et al. [CBK12b] and relaxed
the assumption of subsonic flows in EBTEL.
Additionally the Mach numbers and velocities produced are in better agreement with field-aligned
hydrodynamic simulations.
The IDL software implementation of this model is referred to as EBTEL3-IDL.
EBTEL3-IDL uses an adaptive time grid to ensure the appropriate timescales are resolved in the
impulsive phase.
ebtelplusplus#
Barnes et al. [BCB16] improved upon the implementation of Cargill et al. [CBK12b]
by extending the treatment to the two-fluid hydrodynamic equations, allowing for differential heating
between electrons and ions.
They also introduced a slightly modified approach for calculating the the \(c_1\) parameter during
the conductive cooling phase [see Appendix A of BCB16].
Modifications to include area expansion in the manner of Cargill et al. [CBKB22] were subsequently added
as well as the ability to vary the abundance model for the radiative losses as a function of time [RUBC24].
Furthermore, the resulting equations are solved using a Runge-Kutta Cash-Karp integration method
[see section 16.2 of PTVF92] and an (optional) adaptive time-stepping technique
to ensure the principal physical timescales are resolved at each phase of the loop evolution.
The software implementation of this version of the model is referred to as ebtelplusplus (or ebtel++).
The majority of the software is implemented in C++ for computational efficiency and is wrapped in Python
to enable easy installation and a user-friendly API.
This is the implementation provided by this software package.
ebtelplusplus has been benchmarked against both EBTEL-IDL as well as more advanced field-aligned
hydrodynamic models [BCB16].