 Liquid xenon is being used in <unk> for measurements of gamma rays as well as a medium for detecting hypothetical weakly interacting massive particles , or <unk> . When a <unk> <unk> with a xenon nucleus , it is predicted to <unk> enough energy to cause ionization and <unk> . Liquid xenon is useful for this type of experiment due to its high density which makes dark matter interaction more likely and permits a quiet detector due to self @-@ shielding . 
