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