BioSAXS beamline characteristics

G1 Station:

E = 9.8833 keV (1.254489 Å), end of the run, 7/23

beam diameter (250 µm x 250 µm)

Flux = 5.9 x 10¹¹ photons/s (5/21/17)

Flux = 5.7 x 10¹¹ photons/s (5/31/17)

G1 Station:

E = 9.846 keV (1.259 Å)

beam diameter (250 µm x 250 µm)

Flux = 1.24 x 10¹² photons/s (start of run)

Flux = 1.08 x 10¹² photons/s (2/8)

Note: transient intensity drops by as much as 60% were observed roughly every 12 hr throughout this run. This problem was eventually located in the upstream beamline optics (a heat transfer issue) and resolved, but only at the end of the BioSAXS run. Since the change was very slow, it did n ot affect sample normalization and would be noticeable only as weaker-than-expected signals lasting few hours twice a day. You can check to see if you were affected by comparing the I1 counter values at various times located in the image header files. At start of run, I1 = 375000 counts/s.

G1 Station:

E = 9.8528 keV (1.2584 Å)

beam diameter (250 µm x 250 µm)

November 11:

Flux = 8.4 x 10¹¹ photons/s

November 4:

Flux = (am) 7.5 x 10¹¹ photons/s
(re-optimized to 1.2 x 10¹² photons/s based on beamstop reading)

October 29:

Flux = 1.1 x 10¹² photons/s

October 26:

Flux = 6.5 x 10¹¹ photons/s

Standards concentration

Lysozyme - 4.21 mg/ml ± 0.03 mg/ml

Glucose Isomerase - 0.33 mg/ml ± 0.004mg/ml

November 9:

Lysozyme - 4.00 mg/ml ± 0.01 mg/ml

G1 Station:

Beam diameter 250 µm x 250 µm

May 21:

E = 9.781 keV (1.267 Å)

Flux = 7.76 x 10¹¹ photons/s @ 124 ma

June 1:

E = 9.781 keV (1.267 Å)

Flux = 9.0 x 10¹¹ photons/s @ 105 ma

Standards concentration

Lysozyme - 4.44 mg/ml ± 0.01 mg/ml

Glucose Isomerase - 0.44 mg/ml ± 0.004 mg/ml

G1 Station:

Beam diameter 250 µm x 250 µm

Note: some SEC runs may have used 250 micron (V) by 500 micron (H) beam with approx 8 x 10¹¹ photons/s flux)

March 16:

E = 9.822 keV (1.262 Å)

Flux = 4.35 x 10¹¹ photons/s @ 100 ma

March 30:

E = 9.822 keV (1.262 Å)

Flux = 4.42 x 10¹¹ photons/s @ 99 ma

April 1:

E = 9.822 keV (1.262 Å)

Flux = 3.26 x 10¹¹ photons/s @ 99 ma

Standards concentration

Lysozyme - 4.12 mg/ml ± 0.03 mg/ml

Glucose Isomerase - 0.45 mg/ml ± 0.01mg/ml

G1 Station:

E = 9.962 keV (1.245 Å)

Beam diameter 250 µm x 250 µm

Flux (photons/s) = 8.4 x 10¹¹ @ 92.5 ma on 11/6

• 7.3 x 10¹¹ @ 92 ma 11/11
• 3.6 x 10¹¹ @ 92 ma 11/14
• 5.9 x 10¹¹ @ 92 ma on 11/18
• 9.9 x 10¹¹ @ 92 ma on 11/25 (500 µm x 250 µm)
• 5.6 x 10¹¹ @ 91.4 ma on 12/2

Note: we experienced flux variations from day to day during this run.

Beamstop counter readings (“diode”) in the image headers can be used to estimate actual flux. Conversion factor is 5.56 x 10¹¹ photons/s per 222991 counts/s on beamstop diode.

Minimum sample volumes:
using the robot 25 µL
manual loading 20 µL
recommended working volume 30 µL

Detector: dual Pilatus 100K-S SAXS/WAXS

q-space range:
qmin = 0.0075 - 0.28 Å^-1
qmax = 0.22 - 0.8 Å^-1

Recommended sample exposure: 10 frames @ 2 s each (20 s)

Standards concentration

Lysozyme - 4.27 mg/ml ± 0.01 mg/ml

Glucose Isomerase - 0.47 mg/ml ± 0.01mg/ml

G1 Station:

E = 9.963 keV (1.244 Å)

Beam diameter 250 µm x 250 µm

Flux = 3.63 x 10¹¹ photons/s @ 51 ma

Minimum sample volumes:
using the robot 25 µL
manual loading 20 µL
recommended working volume 30 µL

Detector: dual Pilatus 100K-S SAXS/WAXS

q-space range:
qmin = 0.007 Å^-1
qmax = 0.7 Å^-1

Recommended sample exposure: 10 frames @ 2 s each (20 s)

Standards concentration

Lysozyme - 4.14 mg/ml ± 0.02 mg/ml

Glucose Isomerase - 0.577 mg/ml ± 0.01mg/ml

G1 Station: primary station for BioSAXS experiments

Note: this was a transitional period in the synchrotron upgrade plan that required running with a temporary 30 cm undulator at variable and lower than normal positron currents.

Energy = 11.75 keV (1.055 Å)

Beam diameter 250 µm x 500 µm

Detector: dual Pilatus 100K-S SAXS/WAXS

q-space range:
qmin = 0.007 Å^-1
qmax = 0.7 Å^-1

F1 Station: only used during BioSAXS workshops

Energy = 12.686 keV (0.97733 Å)

Detector = Dectris Pilatus 100k S  (SAXS only)

Sample-to-detector distance = 1140 mm

Beam diameter = 250 µm x 250 µm

Flux = 1.5 x 10¹¹ photons/s

Minimum sample volumes:
using the robot 25 µL
manual loading 20 µL
recommended working volume 30 µL

q_space range: 0.0164 to 0.45 Å^-1
(using improved SAXS.cfg mask created after class end)

Standards concentration

Lysozyme - 4.33 mg/ml ± 0.02

Glucose Isomerase - 0.625 mg/ml ± 0.01

G1 Station:

E = 9.968 keV (1.257 Å) (as of 10/18/2013)

Beam diameter 250 µm x 250 µm

Flux = 1.6 x 10¹¹ photons/s (as of 10/18/2013)

Minimum sample volumes:
        using the robot 25 µL
        manual loading  20 µL
        recommended working volume 30 µL

Detector: dual Pilatus 100K-S SAXS/WAXS

q-space range:
        qmin = 0.007 Å^-1
        qmax = 0.7 Å^-1

Recommended sample exposure: 10 frames @ 2 s each (20 s total).

F2 Station:

E = 9.881 keV (decommissioned 6/13/2013)

Beam diameter: 250 µm × 250 µm

Flux = 2 x 10¹⁰ photons/s

Minimum sample volumes:

using the robot: 15 µL
manual loading: 5 µL (practical limit)
recommended working volume: 30 µL

Detector: dual Pilatus 100K-S SAXS/WAXS

q-space range:

qmin = 0.008 Å^-1
qmax = 0.8 Å^-1

Total exposure times: 300-600 s

Typical throughput: 80 sample plugs per 24 hours (about 20 protein samples including buffer, dilutions, and cleaning).