Disclosed is a system for measuring a chemical in a subsurface formation comprising housing component traversable within the well, a guide extending down the well from a fixed location being operatively connected to the housing, a radiation source, and an optical pathway between a sample and detector wherein the detector is located at the ground surface. Also disclosed is a method for reducing long distance transmission of radiation comprising placing a radiation source in a housing, placing a housing down in a well bore, lowering a spectrometer down the well bore, and controlling movement of a spectrometer by a guide wire controller at the ground surface. Further disclosed is a method of radiating a sample comprising, transmitting the radiation through at least one optical pathway, interacting a sample with the radiation, producing characteristic radiation from the sample, and transmitting by an optical pathway to a detector located in a spectrometer.