A METHOD FOR DOWNHOLE, NON-ISOTOPIC GENERATION OF NEUTRONS AND AN APPARATUS FOR USE WHEN PRACTISING THE METHOD

摘要

A method for downhole generation of non -radioactive neutron radiation (28) arranged so as to be able to generate reverberation, particularly gamma radiation, from the surroundings (5) of a borehole (3), the method comprising the steps of : exciting laser light (14) in a multistage laser light booster (12) by means of a pump-type laser light source (13) so as to form a pulsed laser light (14a), the incoming light energy being concentrated in restricted laser light pulses representing a higher amount of light energy than that of the continuous flux of laser light (14); forming a drop (16a) of a neutron -enriched fluid (16) within a space (23) in a vacuum chamber (15); - focussing the pulsed secondary laser light rays (14b, 14c), which are directed toward the drop (16a) from substantially diametrically opposite directions, at a point in the drop (16a), the drop (16a) consequently being compressed and heated so as to cause the neutron -enriched fluid in the drop (16a) to emit neutron radiation (28) to the surroundings (5), thereby forming a high -energy reverberation, at least in the gamma frequency range, from the surroundings (5). An apparatus (1) for use when practising the method.