A sample holder for an X-ray analysis apparatus, the sample holder for holding a hollow tube holding a sample, the sample holder comprising: a base portion having an opening for an X-ray beam; a first thermal transport member on the base portion on one lateral side of the opening and a second thermal transport member on the other lateral side of the opening; a compression element, for compressing both the first and second thermal transport members to urge the first and second thermal transport members together to hold the hollow tube; wherein the first and second thermal transport members are deformable and are arranged to compress the hollow tube laterally to hold the hollow tube such that: (i) the X-ray beam can pass through the hollow tube without intersecting any part of the sample holder, and (ii) there can be thermal contact between the hollow tube and the thermal transport members along the length of the hollow tube and around at least part of the circumference of the hollow tube to conduct heat between the hollow tube and the base portion through the thermal transport members; and characterised in that either (a) the first and second thermal transport members (36, 38) are elastic and are softer than the base portion and softer than the compression element or (b) the first and second thermal transport members (36,38) are of graphite or graphenic carbon, or aluminium, gallium, indium or an alloy thereof. a base portion having an opening for an X-ray beam; a first thermal transport member on the base portion on one lateral side of the opening and a second thermal transport member on the other lateral side of the opening; a compression element, for compressing both the first and second thermal transport members to urge the first and second thermal transport members together to hold the hollow tube; wherein the first and second thermal transport members are deformable and are arranged to compress the hollow tube laterally to hold the hollow tube such that: (i) the X-ray beam can pass through the hollow tube without intersecting any part of the sample holder, and (ii) there can be thermal contact between the hollow tube and the thermal transport members along the length of the hollow tube and around at least part of the circumference of the hollow tube to conduct heat between the hollow tube and the base portion through the thermal transport members; and characterised in that either (a) the first and second thermal transport members (36, 38) are elastic and are softer than the base portion and softer than the compression element or (b) the first and second thermal transport members (36,38) are of graphite or graphenic carbon, or aluminium, gallium, indium or an alloy thereof. (i) the X-ray beam can pass through the hollow tube without intersecting any part of the sample holder, and (ii) there can be thermal contact between the hollow tube and the thermal transport members along the length of the hollow tube and around at least part of the circumference of the hollow tube to conduct heat between the hollow tube and the base portion through the thermal transport members; and characterised in that either (a) the first and second thermal transport members (36, 38) are elastic and are softer than the base portion and softer than the compression element or (b) the first and second thermal transport members (36,38) are of graphite or graphenic carbon, or aluminium, gallium, indium or an alloy thereof.