Detection system including avalanche photodiode for use in harsh environments

A detection system for detecting gamma rays, the detection system comprising:

• a scintillator crystal for receiving at least one gamma ray and generating at least one ultraviolet ray;
• an avalanche photodiode for detecting the ultraviolet ray wherein the avalanche photodiode comprises:
• a substrate having a first dopant;
• a first layer having the first dopant, positioned on top of the substrate;
• a second layer having a second dopant, positioned on top of the first layer;
• a third layer having a second dopant, positioned on top of the second layer;
• a passivation layer for providing electrical passivation on a surface of the avalanche photodiode;
• a phosphorous silicate glass layer for limiting mobile ion transport, positioned on top of the third layer;
• and
• a pair of metal electrodes for providing an ohmic contact wherein a first electrode is positioned below the substrate and a second electrode is positioned above the third layer;
• wherein the avalanche photodiode comprises a first sidewall and a second sidewall forming a sloped mesa shape;
• and
• wherein the avalanche photodiode operates in an environment comprising a temperature approximately equal to 150 degrees Celsius;
• and
• a lens structure for focusing the ultraviolet ray from the scintillator crystal to the avalanche photodiode.