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Where do photons go
When they come out of the beamline and hit my crystal
Elastic scattering
Elastic scattering
Inelastic scattering
Photonuclear absorption
Photonuclear absorption
Photoelectric absorption
Photoelectric absorptione-
+
Fluorescence
+
Fluorescence
e-
+
Photoelectric absorption
Photoelectric absorptione-
+
Secondary ionization
e-
Secondary ionization
e-
e-
+
Secondary ionization
Secondary ionization
Secondary ionization
e-
+
Secondary ionization
e-
e-
e-
e-
e-
e-
+
Secondary ionization
e-
e-
e-
e-
e-
e-
e-
e-
e-
+
+
+
+
+
+
+
++
Secondary ionization
e-
e-
e-
e-
e-
e-
+
+
+
+
+
+
+
+
e-
e-
+
e-
Secondary ionization
e-
e-
e-
e-
e-
e-
+
+
+
+
+
+
+
++
Where do photons go?
beamstop
Transmitted (98%)
Protein1A x-rays
Where do photons go?
beamstop
elastic scattering (6%)
Transmitted (98%)
Protein1A x-rays
Where do photons go?
beamstop
elastic scattering (6%)
Transmitted (98%)
inelastic scattering (7%)
Protein1A x-rays
Where do photons go?
beamstop
elastic scattering (6%)
Transmitted (98%)
inelastic scattering (7%)
Protein1A x-rays
Re-emitted (99%) Absorbed (~0%)
Where do photons go?
beamstop
elastic scattering (6%)
Transmitted (98%)
inelastic scattering (7%) Photoelectric (87%)
Protein1A x-rays
Re-emitted (99%) Absorbed (~0%)
Where do photons go?
beamstop
elastic scattering (6%)
Transmitted (98%)
inelastic scattering (7%) Photoelectric (87%)
Protein1A x-rays
Re-emitted (~0%) Absorbed (99%)Re-emitted (99%) Absorbed (~0%)
Where do photons go?
beamstop
elastic scattering (6%)
Transmitted (98%)
useful/absorbed energy: 7.3%
inelastic scattering (7%) Photoelectric (87%)
Protein1A x-rays
Re-emitted (~0%) Absorbed (99%)Re-emitted (99%) Absorbed (~0%)
Where do photons go?
beamstop
elastic scattering (6%)
Transmitted (97%)
useful/absorbed energy: 7.6%
inelastic scattering (5%) Photoelectric (88%)
SelenoProtein1A x-rays
Re-emitted (~0%) Absorbed (99%)Re-emitted (99%) Absorbed (~0%)
Where do photons go?
beamstop
elastic scattering (2%)
Transmitted (91%)
useful/absorbed energy: 5.1%
inelastic scattering (2%) Photoelectric (96%)
SelenoProtein0.92A x-rays
Re-emitted (57%) Absorbed (44%)Re-emitted (99%) Absorbed (~0%)
just above the edge
Where do photons go?
beamstop
elastic scattering (2%)
Transmitted (90%)
useful/absorbed energy: 5.1%
inelastic scattering (2%) Photoelectric (96%)
SelenoProtein0.97A x-rays
Re-emitted (60%) Absorbed (40%)Re-emitted (99%) Absorbed (~0%)
far above the edge
Background scattering
Resolution (Ǻ)
Ele
ctro
n e
qu
ival
ents
The form-factor of the cryostream
20 10 5 4 3 2.5 2 1.8 1.6 1.4 1.2 1
0
2
4
6
8
10
12
14
1
6
measured
theoretical
Background scattering
0
50
100
150
200
250
300
0.00 0.07 0.13 0.20 0.27 0.33 0.40 0.47
35mm air
200um water
everything else
Resolution (Ǻ)
Ph
oto
ns/
s/p
ixel
Se edge with detector at 100 mm
7.5 3.8 2.5 1.9 1.5 1.2 1.1
