Overview
Beam line 4-1 is a high-flux wiggler station optimized for x-ray absorption spectroscopy (XANES and EXAFS) in the 5–38 keV range, covering transition metals, lanthanides, actinides and P-block elements. BL4-1 accommodates radioactive materials (RAM) samples with radionuclides based on radiotoxicity level, activity, shielding requirements and experimental needs. The station features an LN2-cooled double-crystal Si(220) monochromator with energy resolution up to 10-5(ΔE/E) and small vertical entrance slits to reduce intensity glitches. Equipment includes a Canberra 30-element Ge detector for dilute samples, a passivated implanted planar silicon (PIPS) semiconductor detector for fluorescence detection, ionization chambers for transmission data, and cryostats for maintaining samples at 4–273 K, with most experiments at 77 K. A motorized sample holder and a flammable gas cabinet support in-situ studies.
Source: 20-pole, 2-Tesla wiggler side station, ≤ 0.75 mrad acceptance
Additional information about RAM
- Advanced notifications of your intent to ship RAM are required 30-, 7-, and 1-days in advance.
- Only approved holders listed in the SSRL radioactive sample holder catalog may be used
- Shipping containers and practices must conform closely to the instructions provided to users following the submission of 7-day notifications
ALL samples containing radioisotopes are considered to be RAM by DOE, and we are required to control their movement on site. This requirement would include, for example, natural samples containing only 20 ppm of natural U. For this reason, ALL RAM samples require advanced notification and approval prior to shipment. Please help us to comply with these requirements by providing full information regarding the isotope compositions and activities of your samples when you request beam time and submit your notifications.
Source —
20-pole, 2-Tesla wiggler side station, ≤ 0.75 mrad acceptance
Status —
Beamline Parameters —
| Energy Range | Resolution ΔE/E | Spot Size | Flux | |
|---|---|---|---|---|
| Unfocused | 5000-38000 eV | 1 x 10-4 | 4 x 12 mm2 | 2 x 1012 ph/sec |
Optics —
| Monochromator |
|---|
| Si(220), ϕ = 0o & 90o. double-crystal, variable-exit geometry |
Instrumentation —
| Detectors | Canberra 30-element germanium solid state detector Passivated implanted planar silicon (PIPS) semiconductor detector Ionization chambers |
|---|---|
| Ancillary | Goniometers for grazing-incidence XAS Soller slits and scatter guards Liquid nitrogen cryostats Motorized multiple solid sample holder Flammable gas cabinet |
Sample Environment —
| Standard | 4-8 slot motorized sample stage with 3 x 20 x 1 mm single sample size Flat wafer samples up to 2.5 cm diameter Ambient pressure samples Sample temperatures between 10-200 K (cryostats) |
|---|---|
| Non-Standard | For radioactive samples (RAM), refer to: http://www-ssrl.slac.stanford.edu/content/safety/radioactive-materials-ssrl Radioactive sample contact person: Matt Padilla: mpadilla@slac.stanford.edu |
Absorption —
| N/A |
|---|
