Work Package 9: Analysis and presentation of new results
Figure
1: One of the first measurements using 12 MeV C4+
+ Ne(20mTorr) taken in July 28, 2014 with the new data acquisition
system. W=1525 eV F=4. The big spot on the PSD is the 1s2s2p 4P
line of C3+ while the next two lines the 1s2s2p
2P- and 1s2s2p 2P+. Slight
misalignment of peaks along the x-direction caused by insufficient
mu-metal shielding between gas cell and spectrometer. The individual
projections along the x-direction (energy dispersion axis) and the
y-direction (focusing axis) are seen on the right together with
the signal from the sum of all 4 signals.
Figure
2: Same as for Fig. 1, but with additional mu-metal shielding
installed between gas cell and collision chamber. All peaks are
now seen to be aligned.
Figure
3: (a) Measured zero-degree Auger emission spectra for 12
MeV C4+ mixed beam (1s2+, 1s2s 3S)
state in collisions with Ne, He, H2 and Ar. The resulting
Auger lines have been identified as belonging to the three-electron
electron states 1s2l2l΄ 2,4L indicated. The spectra have
been transformed to the rest frame of the projectile and the electron
yield has been normalized to the incident beam current and gas pressure.
(b): As in (α) but for 18 MeV C4+ beam in collisions
with Ne and Ar gas targets. (c): Experimentally determined ratios
(left scale) for R = 4P / (2P+ +2P_)
and (right scale in red) for R΄ = 2P+/2P-
of the production cross sections of (a) and (b). Also shown for
comparison are the results of the previously published experimental
data from WMU [16]. Corrections for both the 1s2s2p 4P
life time effects and TE have also been included.Results
presented at CDAMOP 2015 meeting in New Delhi and will appear as
a proceedings publication.
Description of work package
Work Package
9
Start:
Month 19
Finish:
Month 48
Cost:
Title:
WP9:
Analysis and presentation of new results
Description:
Research Teams:
RT1, RT2, RT3, RT4
9.1 Homebuilt Software
for data analysis: Typical data
analysis has to do with fitting Auger lines (with specialized peak fitting
software) and extracting the absolute single and double differential cross sections
as a function of collision energy. The technique of 00Auger
projectile spectroscopy is well known for its ability to obtain such results
for each state, as long as the observed states are well resolved in the
spectra. This allows for very stringent tests of theory
9.2 Analysis of all
data: Total production cross sections will also be
determined using theoretical structure information (usually Hartree-Fock
codes like Cowan’s etc. [Zou08a]) for the Auger yield and the angular
distribution probability.
9.3 Presentation of new
results within research groups:
From the determined cross sections for the 4P and the 2P
lines we shall eventually extract a value for the ratio R as a function of
collision energy. Cascade contributions will be computed using various codes
already developed by Zouros and Sulik [Zou08a].
9.4 Discussions of new
results - reevaluation of what to measure: We also have extensive contact with theorists who
will be interested to compare their calculations to our new data.
Deliverables:
1
Report and part of BS, MS or PhD thesis, software data analysis programs
WP9: Table of Activities in progress
Completed
Activity
Target Date
1rst beam time - 2 MeV p -
search for Ne KLL Auger - general tests
Apr 2014
2nd beam time - 2 MeV p -
seach for Ne KLL Auger - more tests
May 2014
3rd beam time - 12 MeV C4+
- tests with projectile Auger
Jul 2014
4rth beam time:
- 3 MeV p - search for Ne
KLL target - Auger energy calibration
- 12 MeV C4+ -
more tests with projectile Auger
Sep 2014
Analysis of results of
beam time Sep 9-12/2014
Oct 2014
Accelerator down time for
maintenance, trouble shooting and testing terminal gas stripper
Oct 2014
5th beam time:
5-7/11: 3 MeV p - search
for Ne KLL target - Auger energy calibration
Nov 2014
6th beam time:
17-19/12: 3 MeV p - determination
of Ne KLL target Auger energy calibration - found absolute
efficiency of MCP around 35%
Dec 2014
7th beam time:
12-17/1: 12 MeV C4+
- more tests with projectile Auger (participation of Prof.
Omer Sise)
Jan 2015
8th beam time:
31/1-4/2: 12 MeV C4+
- more tests with projectile Auger, 4P and biased gas cell
5/2: 18 MeV C4+
- more tests with projectile Auger, 4P and biased gas cell
Feb 2015
9th beam time:
4-10/11: 9, 12, 18 MeV C4+
- first use of post strippers, tests of strippers and metastable
fraction produced, biased gas cell results and identification
of metastable 1s2p24Pe
Nov 2015
Analysis of results of
9th beam time
Nov 2015
Final Report on electron measurements
at the TANDEM ready - work package completed
B. Sulik and N. Stolterfoht, Auger electron spectroscopy
of target atoms, in Accelerator based atomic physics techniques
and applications, Eds. S M Shafroth and J C Austin (American Institute
of Physics, Woodbury, NY, 1997), Ch. 12, pp. 377-425.
(6.6 MB)
M.E. Rudd, Y.-K. Kim, D.H. Madison and T.J. Gay, Electron
production in proton collisions with atoms and molecules: energy
distributions, Rev.
Mod. Phys. 64 (1992) 441-490. (Partiicularly the section on
Instrumentation and Error Analysis)
(8.5 MB)
D.-H. Lee, Electron-electron interaction in ion-atom collisions studied by projectile state-resolved Auger
electron spectroscopy, Ph. D. thesis, Kansas State University - 1990 (unpublished).
(22.4 MB)
T.J.M. Zouros and D.-H. Lee, Zero-degree Auger electron
spectroscopy of Projectile Ions, in Accelerator based atomic
physics techniques and applications, Eds. S M Shafroth and J C
Austin (American Institute of Physics, Woodbury, NY, 1997), Ch.
13, pp. 427-479.
(1.9 MB)
E.H.A. Granneman and M.J. Van der Wiel, Transport, dispersion
and detection of electrons, ions and neutrals in Handbook
of Synchrotron Radiation, edited by E.E. Koch, (North Holland,
Amsterdam, 1983) vol. 1A, Chapter 6, pp. 367-456.
(14.8 MB)
Casey C. Farnell, Cody C. Farnell, Shawn C. Farnell and John
D. Williams, Electrostatic Analyzers with Application to Electric
Propulsion Testing33st International Electric Propulsion
Conference, The George Washington University, USA October 6 –
10, 2013
(3.2 MB)