... dT )/(dT /dP ) = (dV /dT )/G. The volume of the absorber for our array of ten bolometers is = 10-19 m3 , and the material parameter for aluminium is = 1.2 109 W · m-3 · K-5 ; the thermal conductivity is thus G = 3.6 10-12 W/K at 280 mK phonon temperature ...