Sample Delivery Methods

Methods

Supported Methods

The table below summarizes the current sample handling capabilities at the LCLS. We are currently in the process of developing new sample delivery techniques, and users are encouraged to contact the Sample Environment Department to discuss requirements unique to their experiment - we are flexible.

Technique Size Vacuum Ambient
Liquid Jets   1 µm - 10 µm
20 µm - 500 µm ⛔️ ✅    ♻️
Liquid Sheets
< 1 µm ✅    ♻️
1 µm - 10 µm ⛔️ ✅    ♻️
10 µm - 250 µm ​​⛔️ ✅   ♻️
Liquid Drops 40 µm - 6 0 µm ​​⛔️
Double Flow Focusing All available sizes
Electrospinning (MESH) All available sizes
High Viscosity All available sizes
Aerosols All available sizes ⛔️

✅ Available      ⛔️ Not Available     ♻️ Recirculation is available at some endstations.

Descriptions of Sample Delivery Methods

Liquid Recirculation

High flow rate experiments operating in ambient air or in a helium enclosure can be operated in a closed-loop recirculating system when the sample permits. Cylindrical liquid jets from 20 micrometer diameter and larger and liquid sheets of any thickness from a few 10’s of nanometers to several hundred micrometers can be recirculated. The minimum volume of sample needed to fill the swept volume of our recirculating system is typically a few ml for smaller jets, Larger sheets operating at greater than 150 ml/minute require a peristaltic pumping system with a higher swept volume. Details can be found on the pump section of our Equipment page.

Cylindrical Liquid Jets

Single fluid “Rayleigh Jets” can be used for experiments in which larger diameter,  >20 micrometers, jets with high flow rates are acceptable. These jets are often used for pump-probe spectroscopies at the XPP and XCS endstations with a recirculating system in a helium enclosure. They can also be operated in vacuum without recirculation however their reliability is much higher at pressures closer to atmospheric. The nozzles are made of straight walled polished quartz tubing but other materials are available. These jets are fairly reliable and users are usually able to operate on their own after a short training session.

Gas Accelerated, GDVN, or flow focused jets can be made much smaller than single fluid nozzles. They are commonly operated in vacuum for serial crystallography experiments – the reduced jet diameter, 1 to 10 micrometers reduces the background scatter. Flow rates can be as low as 10 microliters per minute but typically these nozzles are run at 20 microliters per minute in order to get longer, more stable jets for the experiments.

Liquid Sheets

  • >10 micrometers. Straight walled nozzles are used to make sheets from 13 micrometers thick and larger. As with cylindrical jets, these have fairly high flow rate and are operated in ambient conditions.
  • 1 to 10 micrometers – Converging nozzles are useful for making
  • < 1 micrometer – Gas accelerated nozzles make ultra-thin sheets that can be operated in vacuum or atmosphere.

Aerosols

Aerosols are made by nebulization of liquids. GDVN, Electrospray, or gas assisted electrospray have been used. An aerodynamic lens stack made by Uppsala is owned by SLAC and is available to users. Aerosols are used primarily for single particle imaging. Solutions must have high particle density and low amounts of salts, buffers, or any nonvolatile material that cannot be evaporated from the sample.

Other Methods

Other SLAC sample delivery methods - descriptions coming soon.

  • Flow Focusing & Mixers
  • Drop on Demand
  • High Viscosity Injection LCP
  • Electrospray MESH
  • Gas Sources and Cells

Non-SLAC User-owned Equipment

There are some methods not owned by SLAC that have been used at SLAC and may be available through collaboration.

  • Acoustic Levitation
  • Rowed Runner
  • Dipstick