Xcell: mode of operation

The sample is mounted on a loop, then on the user's preferred mounting system. The 3mm hole in the slider exactly mirrors the hole in the top of a goniometer head allowing any type of magnet or pin to be mounted on to the slider. Once the sample is mounted, it can be slid easily into the chamber using the slider Handle.

The chamber is then pressurised with the xenon gas from a cylinder. Valves on the Xcell carefully control the inward and outward flow of the gas preventing the crystal from being disturbed on its mount.

Whilst the crystal is held in the Xcell and the xenon gas is flowing in and out of the chamber, it is important that the crystal does not dry out. To avoid this, the xenon passes through filter paper soaked in mother liquor. The path of the xenon gas is designed to flow through the filter paper and saturate the environment in the chamber with the chosen mother liquor. In addition, the points where the xenon enters and leaves the chamber are positioned as far from the mounted crystal as possible to avoid gas flowing directly over the crystal.

Once the Xcell has been pressurised, a stop valve and quick release system enable the Xcell to be isolated from the xenon supply and moved to wherever needed. Once the Xcell has been vented, the chamber can be opened and the slider pulled from the Xcell with one hand. This allows the user to grab the sample mount with tweezers in the other hand-an important feature when speed is of the essence.

Both the Xcell and the gas transfer line have self-sealing mechanisms to retain the xenon. These isolation systems prevent the loss of xenon gas when the Xcell is disconnected and reconnected to the gas transfer line. Even when the Xcell is reconnected to the gas transfer line, there is no need to vent the gas transfer line as the inlet valve prevents the gas from being rapidly introduced to the cell.