Xavier,
Airport X-ray machines may also have high magnetic fields from the machinery that generates the x-rays. My suggestion would be to contact the airline in advance and explain that you are taking some x-ray sensitive materials with you--I assume you are planning to take them as accompanied baggage. Ask how early you have to get it to them, and at what department, in order to get it hand-inspected before it goes into the cargo hold. My other suggestion is to get it double boxed, with at least 2 inches of packing material between the inner and outer boxes. This will also protect it thermally. You probably know those cargo holds can get down below freezing.
The extra care you take getting them home will be rewarded in the long run by the enjoyment you will get from them.