There is only one orange cryostat at ISIS for which the tails are of small enough diameter to fit into LAD’s non-standard sample tank (see section 3.1). This cryostat has an internal diameter of 100mm, and it will accept any sample whose height does not exceed ~80mm and whose horizontal dimensions will fit within a cylinder of diameter 100mm.

The orange cryostat has the advantage of having a lower minimum temperature (normally 4.2K, or less than 1.5K with the use of a pump) than the CCR. Also the CCR is bottom-loading (i.e. the CCR must be removed from the sample tank in order to change sample) whereas the cryostat has a centre-stick. This means that with the cryostat a sample can be placed in a low temperature environment very quickly which can be an advantage for some experiments (of order 1 hour is required to cool the sample to base temperature with the CCR).

Despite the above advantages, the cryostat is only rarely used on LAD because it gives a much larger neutron background than the CCR and it is much more prone to problems such as blockages. For this reason the LAD manual does not contain detailed information on the operation of the cryostat.

Last Updated 09 Nov 1998