hbr , angular distribution analysis e(0 ) updated , 24.12.2013
DESCRIPTION
HBr , angular distribution analysis E(0 ) Updated , 24.12.2013. Peak “A”. E0,J´=3. E0,J´=4. E. 4 h n ionization / H + formation. H + + Br*. H + + Br. H* + Br*. 3 h n dissociation / H* formation. H* + Br. J´ v´. 2 h n resonance excitation. v´,J´. HX**. Rydb . - PowerPoint PPT PresentationTRANSCRIPT
HBr, angular distribution analysis
E(0)
Updated, 24.12.2013
2.0
1.5
1.0
0.5
0.0
-0.5
-1.0
8642
Peak “A”
E0,J´=3
E0,J´=4
Rydb.
H + Br/Br*
r(HX)J´´ v´´= 0
HX
HX** J´ v´
E
H+X-/Ion-pair/V
v´,J´
H* + Br
H* + Br*
H+ + Br
H + + Br*
2 hn resonance excitation
3 hn dissociation / H* formation
4 hn ionization / H+ formation
2 hn resonance excitation
3 hn dissociation / H* formation
According tohttps://notendur.hi.is/~agust/rannsoknir/papers/jcp121-11802-04.pdf :
where
Unknown(variable in a fit)
Unknown(variables in a fit)
BUT simpler for “non Q branches” (O, S) (i.e. for J´´ ¹ J´):
2 hn resonance excitation
3 hn dissociation / H* formation
https://notendur.hi.is/~agust/rannsoknir/papers/jcp121-11802-04.pdf
…. i.e. independent of the R´s
An alternative way to analyse the angular distribution data is bythe procedure given by Chichinin et al.:https://notendur.hi.is/~agust/rannsoknir/papers/jcp125-034310-06.pdf -which involves the use of relative intensities of spectral lines IQ/IS and IQ/IO
which could be derived from our REMPI spectra:
i
f
ph
HBr(Ji)
HBr**
H* + Br/Br*
1. Determine „b“ factor, via mass resolved REMPI spectra (see p: 9 https://notendur.hi.is/~agust/rannsoknir/papers/jcp125-034310-06.pdf ) from,
2. Determine alignment parameter A20 (<=„b“ )(P: 9, https://notendur.hi.is/~agust/rannsoknir/papers/jcp125-034310-06.pdf )
(43)(for Jf = 1)
(24)
(25)
4. Determine the angular distribution for one-photon photodissociation of the unpolarized„f“ state (i.e. w (n,nph)) from
for k = 1 (one photon), where w (n) is the photofragment angular distribution produced by amultiphoton excitation via the intermediate state (i.e. angular distribution derived from our experiments) (see p: 6 in https://notendur.hi.is/~agust/rannsoknir/papers/jcp125-034310-06.pdf )
(1)ph
3. Determine angular distribution (wf(n)) via b –factor (b (f)) determination for„f“(see slide 10): (P:6 (and 9), https://notendur.hi.is/~agust/rannsoknir/papers/jcp125-034310-06.pdf )
(30)
See: http://mathworld.wolfram.com/LegendrePolynomial.html
;Jf = 1
1. Determine „b“ factor, via mass resolved REMPI spectra (see p: 9 https://notendur.hi.is/~agust/rannsoknir/papers/jcp125-034310-06.pdf ) from,
Detailed analysis, see : agust,heima, …./PPT-131219.pptx
a´ c´ d´
a´´ c´´ d´´
HBr; E(0) angular distribution analysis; Areas a´ c´ d´ a" c" d" b**2 b**2
IO IO IQ IS IS IQ/IO IQ/IS IQ/IS IQ/IS IQ/IS IQ/IO IQ/IO IQ/IO S O
J´´ Lorentz Gauss Lorentz Lorentz Gauss Lorentz Lorentz Lorentz Lorentz Lorentz Lorentz Lorentz Lorentz Lorentz J´(S) Lorentz J´(O)
0 73217 10297 7294 7,110518 1,666667 3 0 1,422104 2
1 263790 24571 18460 10,73583 3,333333 2,5 0,2 1,208299 3
2 427040 38185 28692 11,18345 4,166667 2,333333 0,133333 16,66667 1,5 0,085714 1,093155 4
3 23416 16781 547620 42857 33308 23,38657 12,77784 4,666667 2,25 0,12 11,66667 1,666667 0,088889 1,163604 5 1,149405 1
4 27174 17033 623810 44897 34919 22,95613 13,89425 5 2,2 0,114286 10 1,75 0,090909 1,211165 6 1,259831 2
5 32831 21523 607140 37550 27657 18,49289 16,16884 5,238095 2,166667 0,111111 9,166667 1,8 0,092308 1,373385 7 1,069499 3
6 43837 28994 558280 31471 16560 12,73536 17,73951 5,416667 2,142857 0,109091 8,666667 1,833333 0,093333 1,477418 8 0,750617 4
7 58895 41854 447480 2555 1797 7,597929 175,1389 5,555556 2,125 0,107692 8,333333 1,857143 0,094118 14,78462 9 0,440264 5
8 53011 41966 281260 5,305691 5,666667 2,111111 0,106667 8,095238 1,875 0,094737 0,299025 6
9 37166 30645 69388 1,866975 5,757576 2,1 0,105882 7,916667 1,888889 0,095238 0,07443 7
10 13743 11193 5,833333 2,090909 0,105263 7,777778 1,9 0,095652
11 2882 2019 5,897436 2,083333 0,104762 7,666667 1,909091 0,096
OVERLAP
OVERLAP av b**2 1,210327 1,057338 4 values
with 1,159578 3 values
V(m+4) av(av) 3 values 1,188578
1,19
av 1,278447 S(J´=2-8)
ATH Gaussian fit to Q lines av 1,159578 O(J´=1-3)
ERGO, (b**2) ca.: 1,2 b: 1,095445or -1,09545
https://notendur.hi.is/~agust/rannsoknir/Crete/XLS-131221.xlsx
2. Determine alignment parameter A20 (<=„b“ )(P: 9, https://notendur.hi.is/~agust/rannsoknir/papers/jcp125-034310-06.pdf )
(43)(for Jf = 1)
(24)
(25)
Alignment parameter A20:http://www.ejournal.unam.mx/rmf/no503/RMF50315.pdf , p:319
-1.0
-0.8
-0.6
-0.4
-0.2
0.0
0.2
0.4
2.01.51.00.50.0-0.5 b
A20(Jf=1)
A20(min) = -1
A20(max) =+0.5
b=1Perpend. domin.
b=-0.5parallel. domin.
https://notendur.hi.is/~agust/rannsoknir/Crete/PXP-131222.pxp; Gr0,Lay0 <= https://notendur.hi.is/~agust/rannsoknir/Crete/XLS-131221.xlsx
-1.0
-0.5
0.0
0.5
2.01.51.00.50.0-0.5
Alignment parameter A20:http://www.ejournal.unam.mx/rmf/no503/RMF50315.pdf , p:319
b factor
A20(Jf)
A20(min;Jf=1) = -1
A20(max;Jf=1) =+0.5
b = 1Perpendicular dominant
b=-0.5parallel dominant
Jf= 1
2 11
Jf =
11 2 1
https://notendur.hi.is/~agust/rannsoknir/Crete/PXP-131222.pxp; Gr0,Lay0 <= https://notendur.hi.is/~agust/rannsoknir/Crete/XLS-131221.xlsx
Our A20 values =A20 (b = 1.1; b2 = 1.2)
f <-<- i transition dominantly perpendicular transition,i.e. S <- P <- S
3. Determine angular distribution (wf(n)) via b –factor (b (f)) determination for„f“(see slide 10): (P:6 (and 9), https://notendur.hi.is/~agust/rannsoknir/papers/jcp125-034310-06.pdf )
(30)
See: http://mathworld.wolfram.com/LegendrePolynomial.html
b (f) = -0,62215
https://notendur.hi.is/~agust/rannsoknir/Crete/XLS-131221.xlsx
;Jf = 1
0.10
0.09
0.08
0.07
0.06
0.05
0.04
0.03
150100500
https://notendur.hi.is/~agust/rannsoknir/Crete/PXP-131222.pxp; Gr1,Lay1<= https://notendur.hi.is/~agust/rannsoknir/Crete/XLS-131221.xlsx
q
wf(n; Jf =1)
J´> 1:
https://notendur.hi.is/~agust/rannsoknir/papers/jcp125-034310-06.pdf:
i.e.:
(https://notendur.hi.is/~agust/rannsoknir/papers/jcp121-11802-04.pdf)
-but to a first approximation (?) bL = 0 for L = 4,6,….
ERGO: the angular distribution shown on slide 18 holds for all Jf´s !-in which case the alteration in angular distribution vs. J observed (Slide 2)is due to the photofragmentation step(?!)
Now what?!How do we derive w (n,nph) ?
(1)ph
How about a „fitting procedure“:
i.e. something like:
q0 180
f i
ph f
Experiment
b(ph)
(1) + A~
-for red coloured parameters unknown => derive b(ph)