There is described a radiation source module comprising: a plurality of radiation source assemblies, each radiation source assembly having a proximal end portion and a distal end portion a first support plate for supporting the proximal end portion of each radiation source assembly and a second support plate for supporting the distal end portion of each radiation source assembly wherein: (i) the first support plate and the second support plate positioned so as to define a radiation emission region therebetween for each radiation source assembly between and (ii) the first support plate comprising a first passageway through which the proximal end portion of each radiation source assembly passes to a remote region with respect to the radiation emission region.
