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Introduction to the electron Boltzmann equation solver
BOLSIG+ (and the data platform LXCat)
Gerjan Hagelaar
Laboratoire Plasma et Conversion d’Énergie (LAPLACE), Université Paul Sabatier Bât 3R2, 118 route de Narbonne
31062 Toulouse Cedex 9, France [email protected]
1
Introduction
In 2005 we released the freeware BOLSIG+ which since then has become a popular tool in low temperature plasma physics:
BOLSIG+ solves the electron Boltzmann equation for field equilibrium: homogeneous electric field E and gas density N, no boundaries, steady state
Input: complete sets of cross sections vs electron impact energy
Output: EEDF, swarm parameters, transport & rate coefficients vs E/N
G. J. M. Hagelaar and L. C. Pitchford, "Solving the Boltzmann equation to obtain electron transport coefficients and rate coefficients for fluid models", Plasma Sources Sci. Technol. 14 (2005) 722-733
Freeware downloadable from www.bolsig.laplace.univ-tsle.fr
2
Different purposes of BOLSIG+
Checking cross sections against swarm data
• Mean velocity
• Anisotropic diffusion coefficients DL & DT
• Townsend coefficient
• vs E/N
• Definitions consistent with measured quantities
• Accuracy
• Validity of 2-term velocity expansion?
Generating data for fluid discharge modeling
• Mobility
• Mean energy
• Rate coefficients
• Energy loss coefficients
• vs E/N or mean energy
• Definitions consistent with coefficients in fluid equations
• Computational speed
• Gradients, boundaries, nonlocal effects: is BOLSIG+ applicable?
Purpose:
Results of primary interest:
Issues:
3
Basic equations
Boltzmann equation:
iz 0
0
1constant
nF d
n t N
0 1( , , ) ( , ) ( ) ( )cosf t n t F F r v r
221/20
0 0 0[ ,{ ( )}]
3
dFe E dC F F
N d Q d N
01
dFeEF
NQ d
m 1/2( )Q
N
1/2
0
0
1F d
[ ]v
f ef f NC f
t m
v E
collision operator acceleration
2-term approximation:
isotropic part (EEDF)
anisotropic part (transport)
1/2(2 / )m
2( / )v
momentum cross section:
substituting
electron density
PT growth model: 1
constantn
n z
altneratively: (SST) creation rate
reduced electric field full set of cross sections
4 Many additional options: AC field, gas mixtures, e-e collisions…
Swarm parameters & fluid coefficients
010 03 3
dFe Ew F d d
N Q d
3/2
00F d
00k F d
Mean energy
Mean velocity
Mobility
Diffusion coefficient
Rate coefficients
Townsend coefficients
…
0
03
dFeN d
Q d
003TD N F d
Q
00F d
N w
5
(for each collision process)
Running BOLSIG+ (1)
6
Running BOLSIG+ (2)
7
Running BOLSIG+ (3)
8
Running BOLSIG+ (4)
9
e-e Coulomb collisions Maxwellize the EEDF
G. J. M. Hagelaar and L. C. Pitchford, Plasma Sources Sci. Technol. 14 (2005) 722-733
electron energy probability function (EEPF): Maxwellian = straight line on semilog plot
without e-e collisions with e-e collisions for different n/N
without e-e
10
EEDF is different in oscillating field
G. J. M. Hagelaar and L. C. Pitchford, Plasma Sources Sci. Technol. 14 (2005) 722-733
DC field AC field with different /N
DC field
11
Anisotropic diffusion theory
BOLSIG+ has recently been extended to calculate separate longitudinal and transverse diffusion coefficients DL and DT using a density gradient expansion [1,2]:
1 ( , ) 1 ( , )
( , , ) ( ) ( , ) ( ) ( )n t n t
f t F n t G HN z N r
r rr v v r v v
0 1( ) ( ) ( )cosG G G v
0
03T
D N F dQ
1/20
1
0 0
1
3 3L T
dGED N D N d w Fd
N Q d Q
2 2 1/21/2 1/20 0 0
0 0 0 0 02
1[ ] 2
3 3 3
dG dF dFE d E d E dC G G w F f
N d Q d N N d d N Q d d QQ
0 1( ) ( ) ( )cosH H H v
[1] J. H. Parker and J. J. Lowke, Phys. Rev. 181, 290 (1969) [2] Phelps and Pitchford, Phys. Rev. A 25, 540 (1982)
1 0H F
Q
One can show that:
G0 solved from additional equation, similar to F0 equation:
1/2 1/2
0 00 00G d H d
12
Anisotropic diffusion coefficients DL & DT
Diffusion coefficient in previous BOLSIG+ versions corresponds to DT
Main interest of DL and DT: analysis of swarm data vs cross section data
Limited interest for fluid models: plasma diffusion (against ambipolar field) essentially different from BOLSIG+, Einstein relation as good or better
DN
(m
-1s-1
)
E/N (Td)
Diffusion coefficient in N2
2
3
kTD
e
DT
DL Einstein
Einstein exact at E/N =0
Einstein relation:
13
BOLSIG+ input data: LXCat database
Input cross section data from by many contributors can be downloaded from LXCat website www.lxcat.net
BOLSIG+ requires complete sets of cross sections: elastic momentum transfer + total inelastics + ionization
LXCat includes online simplified version of BOLSIG+
14
Input data example: Argon cross section sets on LXCat
L. C. Pitchford et al, J. Phys. D 46 (2013) 334001 15
Gas temperature effects at low E/N
For E/N→0 the electron distribution function becomes Maxwellian at gas temperature
To obtain this with BOLSIG+ in molecular gases, it is necessary to include superelastic inverse processes for all low-threshold excitations, with equilibrium upper level populations
Characteristic energy in H2:
300 K = 0.026 eV
We currently are considering how to simplify/automatize the inclusion of collisions with ro-vibrational states, using analytical approximations L. C. Pitchford et al, poster at GEC 2012, Austin 16
How good is 2-term? Generally very good!
BOLSIG+ results have been compared with Monte Carlo simulations [1,2] for many gases and conditions
Generally excellent agreement (within 10% for all results) provided that cross-sections and system described are exactly the same
Even at high E/N, differences between BOLSIG+ and MC do not exceed differences due to assumptions on growth (PT/SST), inelastic angular scattering, energy sharing, etc
Dramatic failure of 2-term approximation claimed by some authors is most likely a misinterpretation of effects of inconsistent cross-sections, conditions, or parameter definitions
[1] G. J. M. Hagelaar, MCIG, Monte-Carlo version of BOLSIG+ (unpublished, 2012)
[2] S. F. Biagi, Nucl. Instr. and Meth. A 421, 234 (1999)
17
Example 1: BOLSIG+ vs MC vs experiments in N2
L. C. Pitchford et al, poster at GEC 2012, Austin
Mobility Townsend coefficient
Comparisons BOLSIG+ vs Monte Carlo (Biagi) vs experimental swarm data for different set of N2 cross sections: BOLSIG+ agrees well with other data
18
Example 2: High E/N in Ar
Without electron creation, runaway set in > 1000 Td
100 1000
1
10
100
1000
no growth
SST
BOLSIG+
MC isotropic
MC forward
ioniz
atio
n r
ate
(1
0-1
6 m
3s
-1)
E/N (Td)
PT
100 10000
10
20
30
40
no growth
SST
BOLSIG+
MC isotropic
MC forward
me
an
en
erg
y (
eV
)
E/N (Td)
PT
Failure of SST for E/N > 700 Td in BOLSIG+ but not in MC
Comparisons BOLSIG+ vs MCIG for different growth models and different assumptions on angular scattering in inelastic collisions: good agreement
Cross sections from Siglo database, www.lxcat.net, retrieved 26/09/2013 19
Example 3: Diffusion in CF4 (notoriously problematic)
Cro
ss s
ecti
on
(m
2)
10 100 100010
23
1024
1025
Einstein
DT
BOLSIG+
MC
DN
(m
-1s
-1)
E/N (Td)
DL
Cross sections from Hayashi data base, www.lxcat.net, retrieved 29/09/2013
Energy (eV)
Q(elastic) << Q(inelastic)
Comparisons of anisotropic diffusion coefficients in CF4 calculated with BOLSIG+ vs MCIG: failure of 2-term density-gradient expansion
Note: Other parameters (, , , k, etc) OK
20
Known exceptions where BOLSIG+ fails
In some gases: large errors in diffusion coefficients while other parameters OK, due to failure of 2-term density-gradient expansion:
DT in Ramsaurer gases (Ar, Kr, Xe)
DL and DT in some molecular gases (CF4) with Q(inelastic) >> Q(elastic) at low energy
Failure of SST (steady-state Townsend) growth model at high E/N, probably related to 2-term approximation
Failure of PT/SST growth models for high electron attachment rate, when attachment frequency >> inverse energy relaxation time, observed also in MC calculations so unrelated with 2-term
21
How good is BOLSIG+ for real plasmas? Depends…
Unlike BOLSIG+, real discharge systems involve boundaries and field variations/reversals/transients which affect the electron kinetics, sometimes severely
BOLSIG+ like ( field equilibruim)
• Swarm experiment • Townsend discharge • DC positive column • Microwave discharge
Essentially different (no local field equibrium)
• Spatial/temporal afterglow • Negative glow • Hollow cathode discharge
Use of BOLSIG+ data for discharges is a practical generalization, often better than assuming a Maxwellian EEDF, but not to be taken literally
Use of BOLSIG+ data vs mean energy (local mean energy approximation) is nothing more than a useful patch between field-equilibrium theory and classical fluid dynamics it cannot describe nonlocal electron kinetics!
Examples:
22
Appendix
Presentation on LXCat at the Gaseous Electronics Conference 2-7 November 2014, Raleigh NC, USA
by Leanne Pitchford
23
LXCat : a web-based, community-wide project on data needed in modeling
low temperature plasmas
Presented by Leanne Pitchford, on behalf of the LXCat team
LAPLACE, Univ Toulouse and CNRS Toulouse, France
www.lxcat.net
LXCat = ELECtron (and ion) SCATtering
Data needs in the field of low temperature plasma science (LTPS) are extensive
Electron-neutral (cross sections and/or transport coefs) Ion-neutral (cross sections and/or transport coefs) Neutral and ion chemistry Plasma surface interactions Radiation ….
Present focus of the LXCat project (electron component): scattering cross sections from ground state targets, over an energy range from thermal to some kV.
The starting point for the LXCat project (2008)
Some on-line compilations of data were available in various formats, more or less complete, accurate – examples : Phelps, Morgan, SIGLO Extensive cross section data sets were available, hard-wired in Fortran codes – example : SF Biagi’s Magbotz code (35000 lines of Fortran code) contains data for over 40 target species. Compilations of cross section data have been published – examples : Itikawa, Hayashi,.. People are generally willing to share data. Many data are available for cross sections for particular processes, transport coefficients in particular gas mixtures….mainly in figure format.
- The DOE report of the workshop on Low Temperature Plasmas (March 2008) stated as a priority to “Establish a clearinghouse for fundamental data for LTPS. A hierarchical evaluation, ranging from rough approximations to accurate and complete datasets, should be created. The data should be brought together, evaluated by experts, and made widely available by using up-to-date Web-based techniques.” - Independently of this assessment, the group in Toulouse (mainly Sergey Pancheshnyi) developed an open access website, into which data can be
uploaded. On-line tools were developed for manipulating data.
LXCat
Conclusions from the public discussion at GEC 2010 - there is considerable interest/need in the GEC community for developing modern
databases and on-line tools for LTPST - a community-wide effort is desirable with a well-identified structure to assure survivability (continuity + good technical solutions to avoid dead-ends) - a number of people are ready to support this effort - many questions need to be addressed ..scope, evaluation, organization, IP,.., overlap with other projects,… - the Toulouse platform is a good starting point
GEC Plasma Data Exchange Project
The Gaseous Electronics Conference agreed to host three workshops focusing on data for modeling LTP’s. 2011 : organization of a workshop at the GEC, poster contributions on noble gases 2012 : organization of a workshop at the GEC, poster contributions on simple molecular gases 2013: organization of a workshop at the GEC, poster contributions on H2O
Most of the data presented in the workshops are now available on LXCat and intercomparisons have been presented in poster sessions at previous GEC’s.
LXCat in 2014
On-line tools
www.lxcat.net
Contributors
Users
Individual databases ~20 at present
(~ 30 people from 12 countries)
S. Pancheshnyi et al., Chem. Phys. 398, 148 (2012)
Contributors to The LXCat project (updated November 2014)
Website conception and development: S Pancheshnyi, France /Switzerland
Electrons: Compilations of cross section data : MC Bordage, V. Puech, LC Pitchford, France; SF
Biagi, UK; WL Morgan, AV Phelps USA; LL Alves and CM Ferreira, Portugal; Kochetov and Napartovich, Russia; Y. Itikawa, (M Hayashi), Japan; L Campbell and M Brunger, Australia + Chris Brion’s library of optical oscillator strengths, Canada
Quantum calculations: J. Tennyson and D. Brown, UK; O. Zatsarinny and K. Bartschat USA; I. Bray
and D. Furst, Australia; Al Stauffer, Canada
Compilations of experimental transport coefficients: transcription of data from publications
S. Chowdhury, France/India; J. de Urquijo, Mexico; LL Alves, Portugal
Ions: L Viehland, AV Phelps, USA; J. de Urquijo, Mexico
On-line Boltzmann solver for electrons: GJM Hagelaar, France
Technical assistance: S. Chowdhury and B Chaudhury, France/India;
Mirror site : J van Dyke, the Netherlands
Data needs depend on the model formulation
Complete sets of cross sections: electron-neutral (ground state) describing momentum-loss, energy-loss processes, and electron number changing processes (ionization, attachment, …)
Boltzmann solver Cross
sections
Swarm
parameters
Swarm parameters: electron transport (mobiity, diffusion), rate coefficients as functions of E/N (if non-Maxwellian) or average energy
Consistency of measured and calculated swarm parameters is a minimum requirement for validation of the cross section data set.
For the electron component, the emphasis in LXCat is on the cross section data, from which swarm parameters can be derived.
33
How to find LXCat
e.g. mobility
«"PREV NEXT"»
FAST"NAVIGATION
PROJECT"STATISTICS
Scattering cross sections: 19 databases | 4 x 162
species | 3.2k records | updated: 25 August 2014
Differential scattering cross sections: 1 database | 1
species | 31 records | updated: 7 November 2013
Interaction potentials: 1 database | 56 x 8 species |
567 records | updated: 23 September 2014
Oscillator strengths: 1 database | 65 species | 150
records | updated: 25 November 2013
Swarm / transport data: 8 databases | 264 x 60
species | 129.8k records | updated: 23 September 2014
Publications, notes and reports: 3 databases | 23
records | updated: 25 August 2013
about the project » news and events » statistics and geography » the lxcat team
About the project
The Plasma Data Exchange Project is a community-based project which was initiated as a result of a public discussion
held at the 2010 Gaseous Electronics Conference (GEC), a leading international meeting for the Low-Temperature
Plasma community. This project aims to address, at least in part, the well-recognized needs for the community to organize
the means of collecting, evaluating and sharing data both for modeling and for interpretation of experiments.
At the heart of the Plasma Data Exchange Project is LXcat (pronounced "elecscat"), an open-access website for
collecting, displaying, and downloading electron and ion scattering cross sections, swarm parameters (mobility, diffusion
coefficient, etc.), reaction rates, energy distribution functions, etc. and other data required for modeling low temperature
plasmas. The available data bases have been contributed by members of the community and are indicated by the
contributor's chosen title.
This is a dynamic website, evolving as contributors add or upgrade data. Check back again frequently.
Suppor ting organizations
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e . g . m o b i l i ty
« " P R E V N E X T " »
S T E P " 1 : " S E L E C T " D A T A " T Y P E " & " C L I C K " N E X T
S C A T T E R I N G " C R O S S " S E C T I O N S
D I F F E R E N T I A L " S C A T T E R I N G " C R O S S " S E C T I O N S
I N T E R A C T I O N " P O T E N T I A L S
O S C I L L A T O R " S T R E N G T H S
S W A R M " / " T R A N S P O R T " D A T A
G L O B A L " S P E C I E S " F I L T E R I N G
E L E C T R O N S
I O N S
C o p yri g h t © 2 0 0 9 -2 0 1 3 , t h e L XC a t t e a m . T h e u se w i t h o u t p ro p e r re f e re n ci n g t o d a t a b a se s a n d so f t w a re u se d i s p ro h i b i t e d . Al l R i g h t s R e se rve d .
d a ta ty p e » d a t a b a se s » ?rst sp e ci e s » se co n d sp e ci e s » d a t a g ro u p s » p ro ce sse s » output
HO M E HO M E HO W T O U SE HO W T O U SE C O N TR IB U T O R S C O N TR IB U T O R S D A T A C EN TER D A T A C EN TER O N L IN E C A L C U L A TIO N S O N L IN E C A L C U L A TIO N S D O C S A N D L IN K S D O C S A N D L IN K S D IS C U S S IO N B O A R D D IS C U S S IO N B O A R D
b r ow s e a n d d ow n l oa d b r ow s e a n d d ow n l oa d
d ow n l oa d f or of f l i n e u s e d ow n l oa d f or of f l i n e u s e
a c c e s s t o p r e vi ou s v e r s i on s a c c e s s t o p r e vi ou s v e r s i on s
e.g. mobility
19 databases | 4 x 162 species | 3.2k records | updated: 25 August 2014
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STEP"1:"SELECT"DATA"TYPE"&"CLICK"NEXT
SCATTERING"CROSS"SECTIONS
DIFFERENTIAL"SCATTERING"CROSS"SECTIONS
INTERACTION"POTENTIALS
OSCILLATOR"STRENGTHS
SWARM"/"TRANSPORT"DATA
GLOBAL"SPECIES"FILTERING
ELECTRONS
IONS
Copyright © 2009-2013, the LXCat team. The use without proper referencing to databases and software used is prohibited. All Rights Reserved.
data type » databases » first species » second species » data groups » processes » output
Databases containing complete sets of cross sections for electron scatter ingfrom ground state neutral atoms and molecules.
The energy range of interest is from 0 to some 100's of eV and higher. A complete set of cross sections consists of
elastic momentum transfer, and total cross sections for the processes of ionization, attachment and excitation.
Complete sets of cross sections are needed as input to a Boltzmann equation solver to determine the electron or ion
energy distribution function.
Databases containing par tial sets of electron-neutral scatter ing crosssections.
Partial sets of electron neutral scattering cross sections are also included on this site. These include additional data
concerning electron collisions with ground state molecules - such as total scattering, total elastic scattering - not used
in the Boltzmann calculations. These also include cross sections for electron impact ionization of metastable or
radicals, needed for the calculation of stepwise ionization, for example.
Databases containing ion-neutral scatter ing cross sections.
The limited ion-neutral cross section data available on this site were derived assuming that the differential scattering
can be reasonably well approximated as the sum of an isotropic part and a backscatter part. These two components
are provided as functions of the center or mass energy.
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e.g. mobility
no fi lter
data type » databases » first species » second species » data groups » processes » output
SI GLO database
DESCRIPTION: The SIGLO database is the "in-house" data used by the group GREPHE at LAPLACE in Toulouse.
The data are taken from different sources as indicated for each gas. Please refer to original sources in publications.
An early version of this data file, "siglo.sec", was distributed with BOLSIG. The main changes in the present version
are :
The format has been changed to be compatible with BOLSIG+.
Scale factors have been incorporated in the data and no longer appear explicitly.
He : The present data are from the compilation of A.V. Phelps (see reference in the Phelps data base).
O2 : We recommend using the data in the Phelps database for this species.
H2 : We recommend using the data in the Phelps database for this species.
Cl2 : The present data are an updated compilation (Jan 2012) by J Gregorio and LC Pitchford.
Cu : Feb 2012. Digitized from Tkachev A N, Fedenev A A and Yakovlenko S I, Laser Phys. vol.17, p. 775 (2007)
Kr : Nov 2012. We re-digitized the data from figs. 1 and 5 in H. Date, Y. Sakai and H. Tagashira, J. Phys. D 22 1478
(1989). With respect to the previous data from this same reference in the SIGLO database, there are some changes in
the threshold values and in the magnitudes of the inelastic cross sections.
CONTACT: LC Pitchford and JP Boeuf
pitchford@@laplace.univ-tlse.fr and jpb@@laplace.univ-tlse.fr
SCATTERING CROSS SECTIONS
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e.g. mobility
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Copyright © 2009-2013, the LXCat team. The use without proper referencing to databases and software used is prohibited. All Rights Reserved.
data type » databases » first species » second species » data groups » processes » output
Ground states
State-specific and gas mixtures
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Ground states
State-specific and gas mixtures
e.g. mobility
Effec%ve Elas%c Excita%on Ioniza%on
«2PREV NEXT2»
no fi lter
STEP25:2SELECT2DATA2GROUPS2&2CLICK2NEXT
SELECT2ALL2&2FILTER2TOOL
Copyright © 2009-2013, the LXCat team. The use without proper referencing to databases and software used is prohibited. All Rights Reserved.
data type » databases » first species » second species » data groups » processes » output
Cross section
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Cross section
e.g. mobility
no fi lter
data type » databases » first species » second species » data groups » processes » output
M organ (Kinema Research & Software)
e / Ar
SI GLO database
Data Group [Ar ] : From compilation of A.V. Phelps.
e / Ar
Phelps database
Data Group [Ar ] : Yamabe, Buckman, and Phelps, Phys. Rev. 27, 1345 (1983) . Revised Oct 1997.
e / Ar
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Morgan (Kinema Research & Software)
SIGLO database
Biagi-v8.9 (Magboltz version 8.9)
e.g. mobility
USERS%MUST%AGREE%TO%THE%TERMS%OF%USE%TOACCESS%DATA%(BROWSE%AND%DOWNLOAD)
YES,%I%have%read%and%understood%»Terms of use
Users acknowledge understanding that LXCAT is a community-based project with open-access databases being freely
provided by individual contributors.
Proper referencing of mater ial retr ieved from this site is essential for thesurvival of the project.
Users further accept that the databases on this site remain property of their respective contributors and are not to be
distributed by third parties or used for commercial purposes. All questions regarding copyright should be addressed to
the LXCAT team.
H ow to reference data
Use of the data from this site in publications should be accompanied by proper references. Original references should be
used where possible and reference should be made to the specific database(s) from which data were retrieved, the LXCat
site address, and the retrieved date. Example:
Biagi-v8.9 database, www.lxcat.net, retrieved on September 28, 2014.
H ow to reference on-line calculations
Swarm coefficient calculated on this site should make reference to both the cross section data in the above format and to
BOLSIG+, the Boltzmann solver used in the calculations:
G.J.M. Hagelaar and L.C. Pitchford, "Solving the Boltzmann equation to obtain electron transport coefficients and
rate coefficients for fluid models", Plasma Sci Sources and Tech 14, 722 (2005).
H ow to reference text documents
Publications and conference proceedings should be referenced according to journal specifications. All unpublished
material on this site should be referenced as "private communication" with the date given on the document, the author's
name, date, and the retrieved date. Example:
Morgan database, private communication, www.lxcat.net, retrieved on September 28, 2014.
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Terms of use
How to reference data
How to reference on-line calculations
How to reference text documents
Proper referencing of material retrieved from this site is essential for the
survival of the project.
42
Time machine tool
Put in place on Nov 12, 2013. All changes in the databases since that time are recorded and data can be recovered as they existed on any day since then.
Important for referencing!!
e.g. mobility
no fi lter
data type » databases » first species » second species » data groups » processes » output
M organ (Kinema Research & Software)
e / Ar
SI GLO database
Data Group [Ar ] : From compilation of A.V. Phelps.
e / Ar
Phelps database
Data Group [Ar ] : Yamabe, Buckman, and Phelps, Phys. Rev. 27, 1345 (1983) . Revised Oct 1997.
e / Ar
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Morgan (Kinema Research & Software)
SIGLO database
Biagi-v8.9 (Magboltz version 8.9)
e.g. mobility
DOWNLOAD'DATADOWNLOAD'IMAGERESCALE'IN'NEW'WINDOWKEEP'WINDOW'AND'GO'BACKGO'BACK
data type » databases » first species » second species » data groups » processes » output
Cross section
SI GLO databaseData Group [Ar ]e / Ar1.
2.
3.
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e.g. mobility
DOWNLOAD'DATADOWNLOAD'IMAGERESCALE'IN'NEW'WINDOWKEEP'WINDOW'AND'GO'BACKGO'BACK
data type » databases » first species » second species » data groups » processes » output
Cross section
SI GLO databaseData Group [Ar ]e / Ar1.
2.
3.
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46
Download TXT, Download PNG, Browse, Re-scale
Linear scale, energy
Acsii text file for off-line use
file header
Data tables
BOLSIG+
Select components of gas mixture
Indicates that some documentation is available on-line
A full version of BOLSIG+ with many more options (e-e collisions, high frequency excitation, ExB,..) is available as freeware.
Results available on-line and by download
Create a temporary LXCat database containing these results
Temporary database containing results from on-line calculations
Compare measured and calculated swarm data
Compare measured and calculated swarm parameters
Gas mixture in temporary database
GEC Plasma Data Exchange Project => evaluation Cluster issue : 2013 J. Phys. D: Appl. Phys. 46 Issue 33 Paper I: Comparisons of sets of electron-neutral scattering cross sections and swarm parameters in noble gases I. Argon LC Pitchford, Alves LL, Bartschat K, Biagi SF, Bordage MC, Phelps AV, Ferreira CM, Hagelaar GJM, Morgan WL, Pancheshnyi S, Puech V, Stauffer A and Zatsarinny O Paper II: Comparisons of sets of electron-neutral scattering cross sections and swarm parameters in noble gases II. Helium and Neon LL Alves, Bordage MC, Biagi SF, Pitchford LC, Zatsarinny O, Bartschat K, Hagelaar GJM, Pancheshnyi S, Ferreira CM, Puech V, Morgan WL and Phelps AV Paper III: Comparisons of sets of electron-neutral scattering cross sections and swarm parameters in noble gases III. Krypton and Xenon MC Bordage, SF Biagi, LC Pitchford, K Bartschat, S Chowdhury, GJM Hagelaar, WL Morgan, V Puech, O Zatsarinny
Paper IV: Computational Methods for Electron-Atom Collisions in Plasma Applications K. Bartschat
LXCAT: some statistics
58
Where are they from?
An average of unique visitors per day
Future directions
• Continuing the enlargement of the databases, on-line tools
new contributors, new data types
• Giving contributors proper recognition for their work
consistent format for referencing among editors
• Continuing effort on evaluation of data some evaluations have been published, others have been presented at the GEC and will be published, & work is in progress for other molecules
• Structure, funding, connection to other sites (e.g. VAMDC)
To contribute, please contact [email protected]