1. of Xenon Collision Dimers in the VUV Energy Region
Rydberg States
of Xenon Collision Dimers
in the VUV Energy Region
Wan-Chun Pan
Dept. of Chemistry, National Tsing Hua University

2. NSRRC
這個工作主要在台灣新竹的NSRRC所進行。Nsrrc屬第三代同步加速器，提供了良好的軟硬x-ray，vuv及ir光源，舊設施已不敷使用，目前正在興建新的儲存環TLS

3. M. Salvermoser and D. E. Murnick , Appl. Phys. Lett., 83, 8 (2003)
Motivation
Xe2* excimer : good medium of VUV light source (lamp,
laser...)
172 nm
M. Salvermoser and D. E. Murnick , Appl. Phys. Lett., 83, 8 (2003)

4. Electronic Configurations:
Xe: [Kr]5s25p6 (1S0)
Xe2:(σg5s)2(σu5s)2(σg5p)2(πg5p)4(πu5p)4
(σu5p)2 X1Σg+
First Rydberg State:
Xe: 5s25p56s[3/2]1
Xe2: 0u- [dissociation limit: Xe(1S0)+Xe(6s[3/2]1)]
Xe2 is an Van der Waals molecule.

5. Xenon Dimer State= Xenon dimer ion state+ Rydberg electron state
R. S. Mulliken, J. Chem. Phys., 52, 5170 (1970)
Xenon
Dimer States
Xenon
Atomic States

6. Xe2 Rydberg States Studied by:
Absorption
M. C. Castex and N. Damany, Chem. Phys. Lett. 13, 158 (1972)
M. C. Castex, Chem. Phys. 5, 448 (1974).
M. C. Castex and N. Damany, Chem. Phys. Lett. 24, 437 (1974)
Laser induced fluorescence
R. H. Lipson, P. E. LaRocque, and B. P. Stoicheff, J. Chem. Phys. 82, 4470 (1985)
K. Tsukiyama and T. Kasuya, J. Mol. Spectrosc. 151, 312 (1992)
Two-photon excitation
W. Gornik, S. Kindt, E. Mathias, and D. Schmidt, J. Chem. Phys. 75, 4595 (1981)
P. M. Dehmer, S. T. Pratt, and J. L. Dehmer, J. Chem. Phys. 85, 13 (1986).
D. S. Green and S. C. Wallace, J. Chem. Phys. 100, 6129 (1994).
S. S. Dimov, J. Y. Cai, and R. H. Lipson, J. Chem. Phys. 101, (1994).
X. K. Hu, D. M. Mao, S. S. Dimov, and R. H. Lipson, J. Chem. Phys. 106, 9411
(1997).
X. K. Hu, D. M. Mao, Y. J. Shi, S. S. Dimov, and R. H. Lipson, J. Chem. Phys.
109, 3944 (1998).
“ Xe2 Rydberg states: Energy < cm-1”
> cm-1

7. Decay processes of Xe* in gas cell:
atomic emission
Xe*...Xe
(one or multi step(s))
collision dimers
Xe* + Xe  Xe2*
Xe2*Xe2Xe+Xe
Xe2*Xe*+XeXe+Xe
Xe2*Xe*+XeXe2*’Xe+Xe
......
J. W. Keto et al., J. Chem. Phys. 84, 709 (1986)

8. Single Photon Excitation
Xe2+
cm-1
Xe+Xe+(2P1/2)
cm-1
C2 Π 3/2u
Xe2+
B2 Π 1/2g
B2 Π 3/2g
100k
Dissociative ionization: Xe2**Xe++Xe+e-
A2 Σ 1/2u
Xe+Xe+(2P3/2)
cm-1
95k
Xe2 *
Xe+Xe*
(ns, nd, ns’)
90k
VUV
Single Photon Excitation
85k
= =
= =
Xe2X1 Σg+
Xe(1S0)

9. Experimental Setup Scanning range:11800-13400 cm-1 R=0.2 cm-1
Xe: %
Pressure: 2-6 torr

10. Beamline Status of NSRRC 21B
with slit =50*100μm

11. Experimental Station of NSRRC 21B2

12. Excited Xenon Atomic States
State (5p5nl[K]J)
Photon Energy (cm-1)
5p513s[3/2]1
5p512s[3/2]1
5p510d[3/2]1
5p510d[1/2]1
5p57s’[1/2]1
5p511s[3/2]1
5p59d[3/2]1
5p59d[1/2]1
5p510s[3/2]1
5p58d[3/2]1
5p58d[1/2]1
5p55d’[3/2]1
5p58s[3/2]1

13. 5p5(2P01/2)7s[1/2] cm-1
先說明量到氙離子 橫軸是雷射能量 再來解釋無法避免觀測到原子雙光子激發共振的光譜

14. 5p5(2P03/2)10d[1/2] cm-1
這兩張圖有點像得到相似的光譜

15. 5p5(2P03/2)11s[3/2] cm-1
換到s能態

16. 5p5(2P03/2)12s[3/2] cm-1
解釋1-19的mark 從低能量到高能量

17. 5p5(2P03/2)13s[3/2] cm-1

18. 5p5(2P03/2)10d[3/2] cm-1

19. 5p5(2P03/2)9d[3/2] cm-1

20. Characteristics of the Signals
The signals appeared at the same IR energy.
There’re two different line shapes in these spectra. One is with the FWHM > 10 cm-1, and the other is FWHM < 5 cm-1.
Intermediate states with the same angular momentum and [K] gave rise to the similar dimer populations in the spectra.

21. Single Photon Excitation
D2 Σ 1/2g
C2 Π 1/2u
cm-1
Xe+Xe+(2P1/2)
C2 Π 3/2u
Xe2+
B2 Π 1/2g
B2 Π 3/2g
100k
Xe+Xe**(ARS)
Xe2**
A2 Σ 1/2u
Xe+Xe+(2P3/2)
cm-1
95k
Xe+Xe**
(ns, nd, ns’)
Xe2 **
Xe2 *
90k
VUV SR
Single Photon Excitation
85k
E(Xe2*)=E[Xe+(2P3/2) ]- E(IR energy)
= =
Xe2X1 Σg+
Xe(1S0)

22. E(Xe2*)=E[Xe+(2P3/2) ]- E(IR energy)
a cm-1 Chem. Phys. 5, 448 (1974)
b cm-1 J. Mol. Spectrosc. 151, 312 (1992)
c cm-1 J. Chem. Phys. 117, 3059 (2002)
0/1/2u
0/1/2u 1u
解釋1-19的mark 從低能量到高能量 22

23. 5p5(2P03/2)10d[1/2] cm-1
a cm-1 Chem. Phys. 5, 448 (1974)
b cm-1 J. Mol. Spectrosc. 151, 312 (1992)
c cm-1 J. Chem. Phys. 117, 3059 (2002)
0/1/2u 1u
0/1/2u 23

24. Summary & Future Works
The transitions to Xe2 Rydberg states in the energy region of cm-1 are observed, and lineshpes are dependence of lifetime of Xe2 states.
The lower atomic states will be excited and the formed dimer states would be detected later. The photoemission spectrum will be detected for comfirming the relaxation processes.

25. Acknowledgement National Science Council (NSC)
National Synchrotron Radiation Research Center (NSRRC)
National Tsing Hua University
Advisors:
Dr. I-Chia Chen (NTHU)
Dr. Yin-Yu Lee (NSRRC)
Co-workers:
Mr. Tzu-Ping Huang (NSRRC)
Mr. Tzan-Yi Dung
Group members of Dr. I-Chia Chen and Dr. Yin-Yu Lee
Dr. Shih-Huang Lee and his group members (NSRRC)

26. Thank you for your attention.