progress in measurements of dissociative recombination crp on atomic and molecular data for plasma...
TRANSCRIPT
![Page 1: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/1.jpg)
Progress in measurements of Progress in measurements of dissociative recombinationdissociative recombination CRP on Atomic and Molecular Data for Plasma ModellingCRP on Atomic and Molecular Data for Plasma Modelling
Mats Larsson
Department of Physics
Stockholm University
![Page 2: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/2.jpg)
Task for Stockholm according Task for Stockholm according to minutes of 2005to minutes of 2005
BeH+ and BeH2+
Problem: The Manne Siegbahn Laboratory reluctant to deal with Be.
![Page 3: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/3.jpg)
Some pointsSome points
The Stockholm group has no national funding for fusion related research
The storage ring CRYRING is still in operation and beam time will be scheduled for the fall of 2007. The decision to shut down the lab was taken 2002, so the damage control has been quite successful!
Beam time during 2008 unclear
![Page 4: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/4.jpg)
ProgressProgress
Experiment on C4D2+
Results on CF2+ and CF3
+
The H3+ and its isotopologues
Development of data base for dissociative recombination
![Page 5: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/5.jpg)
Doubly excited neutral molecule
A2+B
AB+A
A+A+B
+
e-
DR of polyatomic ions
A2B+ + e- (Ee)
For example:
C2H+ + e- C2 + H + 6.60 eV
CH + C + 3.98 eV
C + C + H + 0.43 eV
3 possible DR -
channels
![Page 6: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/6.jpg)
Research programme
What do we measure?:
• Branching fractions of dissociative recombination• Thermal rate constants/Cross sections of dissociative recombination (energy/temperature – dependence)
Which ions do we study?:
- hydrocarbon ions (so far C2H+, C2H2+, C2H3
+, C2H4+, C2D5
+
C3H4+, C3H7
+, C4D9+, C4D2+), CFn+, H3
+
![Page 7: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/7.jpg)
Manne Siegbahn Laboratory
52 meters circumference
![Page 8: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/8.jpg)
ExperimentExperiment
• Long storage time – internal relaxation
• Multi-pass experiment
CRYRING Heavy Ion Storage Ring
electrons
neutrals
ions
Interaction - DR
ions
dipole magnet
SBD
• Electron cooling – well defined beam size
• Ions interact with electrons – dissociative recombination
• Well defined collision energies - velocity matched conditions
• Detect neutral fragments (from DR process)
![Page 9: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/9.jpg)
A2+ + e A + A; no grid
2A
Energy
Pulse height spectrum
![Page 10: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/10.jpg)
A2+ + e A + A; grid with 30% transmission
2A
A
Energy
![Page 11: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/11.jpg)
All fragment from one DR event hit the detector at the same time yield a pulse at an energy corresponding to full beam energy
Gives no information about
how the molecule breaks up
DR Branching DR Branching fractionfraction measurement measurement
C2H++e-
![Page 12: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/12.jpg)
Relate the fragments to different dissociation channels!
C2H++e-
2C
C+H
C
2C+H
DR Branching DR Branching ratioratio measurement measurement
C2H+ + e- C2
+ H
CH + C
C + C + H
e-
γN
βN
αN
T)-2T(1T)-T(10
T)(12TT)-T(10
T)-(1T0T)T(1
TTT
CN
HCN
2CN
H2CN
2
2
2
322
![Page 13: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/13.jpg)
DR Branching DR Branching ratiosratios – Hydrocarbon – Hydrocarbon ionsions
Products Ratio Products Ratio Products Ratio Products Ratio Products Ratio
C2+H 0.43 C2H+H 0.50 C2H2+H 0.29 C2H3+H 0.11 C2D4+D 0.12CH+C 0.39 C2+H2 0.02 C2H+H2 0.06 C2H2+H2 0.06 C2D3+D2 0.00C+C+H 0.18 C2+H+H 0.30 C2H+H+H 0.59 C2H2+H+H 0.66 C2D3+D+D 0.27
CH2+C 0.05 C2+H2+H 0.03 C2H+H2+H 0.10 C2D2+D2+D 0.28CH+CH 0.13 CH3+C 0.01 CH4+C 0.01 C2D2+D+D+D 0.13
CH2+CH 0.03 CH3+CH 0.02 C2D+D2+D2 0.00CH2+CH2 0.04 C2D+D2+D+D 0.00
CD4+CD 0.02CD3+CD2 0.17CD3+C+D2 0.00
C2D5+C2H
+ C2H2+ C2H3
+ C2H4+
Results have been compiled by Janev and Reiter (2002, 2004), and byFlorerscu-Mitchell and Mitchell (2006) and Adams, Poteryaand Babcock (2006)
![Page 14: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/14.jpg)
Viggiano et al. 2005
![Page 15: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/15.jpg)
![Page 16: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/16.jpg)
![Page 17: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/17.jpg)
CF2+ + e CF + F 714
CF3+ + e CF2 + F
8010Ehlerding et al. 2006
![Page 18: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/18.jpg)
![Page 19: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/19.jpg)
New theory: PRL 90, 133201 (2003), PRA 68, 012703 (2003)
CRYRING
2000
Theory
ke[cm3s-1]
2003
AISA
![Page 20: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/20.jpg)
Kreckel et al., Phys. Rev. Lett. 95, 263201 (2005)
TSR
CRYRING
H3+
![Page 21: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/21.jpg)
H3+ D3
+
![Page 22: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/22.jpg)
![Page 23: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/23.jpg)
![Page 24: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/24.jpg)
D2H+ May 2007, CRYRING
![Page 25: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/25.jpg)
![Page 26: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/26.jpg)
![Page 27: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/27.jpg)
-900 V/ring
electrode
H2
para
Gas inlet/2 atm
Solenoid valve
Pinhole flange/ground
electrode
Insulating spacer
Skimmer
![Page 28: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/28.jpg)
Planned experimentPlanned experiment
Ion source will be characterised at the University of Illinois, in Ben McCall’s group with cavity ring-down spectroscopy; critical question: can we produce para-H3
+
using para-H2 as feed gas?
Experiment planned for September 2007, one week of beam time has been allocated
![Page 29: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/29.jpg)
Advanced Intergrated Stationary AfterglowGlosik et al. 2005
![Page 30: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/30.jpg)
Glosik et al. 2005
![Page 31: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/31.jpg)
Summary HSummary H33++
Good agreement experiment-theory for dissociative recombination of H3
+, D3+ and H2D+
Several storage ring experiments agree with each other, but disagree with theory
Stationary afterglow experiments for H3+ give
almost factor 100 lower rate coefficient than storage rings and theory
Para-H3+ will be used in experiment in CRYRING
![Page 32: Progress in measurements of dissociative recombination CRP on Atomic and Molecular Data for Plasma Modelling Mats Larsson Department of Physics Stockholm](https://reader034.vdocuments.site/reader034/viewer/2022051401/56649e615503460f94b5c10c/html5/thumbnails/32.jpg)