Studies of Molecular Photoruptures by using 2 Dimension (2+1) and (3+1) REMPI-TOF
Jingming Long15/09/2010
About project
WHY
WHAT High Energy Rydberg States of Molecules; Spectroscopy and Photofragmentation processes;
A fundamental role in various photochemical and photophysical processes, and so on
Resonance Enhanced Multiphoton Ionization –Time of Flight (REMPI-TOF) ---2D (2+1) REMPI, (3+1)REMPIREMPI-current (University of Iceland,Iceland)
HOW
Synchrotron studies (Paul Sherrer Institute, Switzerland)
Two color, Nanosecond(UV/Vis) + Femtosecond(IR) experiment (University of Bergen,Norway)
About project
CONDITION
Excimer(308nm XeCl)Dye Laser( Lambda Physik) SHG, Sirah, Vaccum chambeDiffusion pump, turbo pumpLecroy oscilloscope 400MHz/2.5GS/Sand so on
Instruments:
Prof. Agust KvaranDr. Victor Huasheng WangPh.D student Kristján Matthíasson
Group:
Collaborators: Professors J.P. Hansen and F. Øyvind , University of Bergen
Dr. Erik Horsdal, University of Aarhusand so on
outoutout
Voltagedevider
HV-2Kv
HX nozzle
TurboPump
TOF
lense
MCP/iondetector
oscilloscope
computer
Excimer Laser
Inout
Dye-Laser
SHG
Timedelay
laser control
Pellin Brocaprism
SHG controlInInIn
REMPI-TOF
Laser beam
Experimental equipment
Experimental equipment
Experimental equipment
HV+
0
-
Iondetector
Titanium sapphire
Dye laser
Field ionizationequipment
SHG
Pumppulse
Delayd/probepulse
Laserpulse
Sketch of the experimental setup to perform two-color experiments
University of Bergen
Main research compounds
i) Hydrogen halides (HX; X = Cl, Br, I)
ii) Halogens, X2 and interhalogens XY; X,Y = Cl, Br, I, X ≠ Y
iii) Freons, CFnXm; X = Cl, Br, I.
25
20
15
10
5
x103
8908089060890408902089000
j 3
-(1), v'=0
J'=1 J'=2 J'=3 J'=4 J'=5 J'=6
V1
J'=3 J'=2
H+
35Cl
+
H35
Cl+
37Cl
+
H37
Cl+
J'=7
J'=1
40
35
30
25
20
15
10
8908089060890408902089000
H37
Cl+
H35
Cl+
35Cl
+
H+
37Cl
+
Typical 2D REMPI-TOF graph
2h
1h
Summarization of the first half year of 2010
Old Dye Laser New Dye Laser
PD REMPI PD REMPI
Tektronix × × × ×
Lecroy × × × ×
PD: Power DependentOld dye laser: LumonicsNew dye laser: Scanmate Pro
Parts of LabVIEW programs
10
9
8
7
6
5
x103
100009500900085008000
9000
8000
7000
6000
5000
200190180170160
11
10
9
8
7
6
5
x103
20001900180017001600
6200
6000
5800
5600
5400
5200
5000
4800
10095908580
Different horizontal resolution at the same vertical resolution for mass spectrum
500 Pnts 10 000 Pnts
50 000 Pnts1000 Pnts
After next triggerWhat’s its value??
Different vertical resolution at the same horizontal resolution for mass spectrum
10
9
8
7
6
5
x103
9600940092009000
35
30
25
20
9600940092009000
Vertical resolution:1/65536
Vertical resolution:1/256
Example---HCl mass spectrum
30
25
20
15
10
5
0
-5
x103
17.217.016.816.616.4x10
3
35Cl+
H35
Cl+
37Cl
+ H37
Cl+
52
51
50
49
x1
03
370365360355
Old data
New data
Improvement
What’s the meaning?
More work for data processing?
Larger file size?
Higher resolution?
More time?
NO
YES
NO
YES
Old New
Manual Automatic
0~255/1Byte500pnts
0~65535/2ByteMax 50000pntsAt 2us
More than 2sTransmitted time
Less than 1s
500*1*(100cm-1/0.1cm-1)Byte
50000*2*(100 cm-1/0.1cm-1)Byte
Larger uncertain,Mass spectrum overlap
Weaker background of spectra? YES Smoothness
Plan for the latter half year of 2010
Perform the experiment of 2D (3+1) REMPI-TOF of HClTry to obtain the unexplored REMPI spectra of High Rydberg statesThen analyze, make assignments…If everything goes well, prepare to write relevant academic papers.
Work with Kari to finish the measurement and analysis of (2+1) REMPI experiment of CF3Br
Plan for the latter half year of 2010
To design and finish a Igor pro “toolkit” contains a series of procedures toProcess REMPI-TOF experimental data, perform simulations and so on, which can be shared by our group easily.For example, the procedures we has finished, REMPI IntegrateV2.2,Mass IdentifyV1.0.
During this period
To optimize the REMPI-TOF LabVIEW program. Make it easy to operate and also be used in teaching of undergraduate experiment.