US 7,321,123 B2
Method and apparatus for radiation detection in a high temperature environment
John Simonetti, Hamilton, N.J. (US); Joel L. Groves, Leonia, N.J. (US); Wolfgang Ziegler, Hightstown, N.J. (US); Art Liberman, Palo Alto, Calif. (US); and Christian Stoller, Princeton Junction, N.J. (US)
Assigned to Schlumberger Technology Corporation, Sugar Land, Tex. (US)
Filed on Dec. 20, 2005, as Appl. No. 11/312,841.
Prior Publication US 2007/0138399 A1, Jun. 21, 2007
Int. Cl. G01T 1/20 (2006.01); G01T 1/24 (2006.01)
U.S. Cl. 250—370.11  [250/256; 250/253; 250/581; 250/301] 1 Claim
OG exemplary drawing
 
1. A radiation detector for operation at high temperatures with mechanical integrity for use in making measurements downhole within a well hole comprising:
a generally cylindrical single crystal LuAP scintillating material for emitting light photons when excited by incident radiation from downhole within a well hole;
a photocathode deposited directly on one end of said generally cylindrical single crystal LuAP scintillating material for emitting electrons and other portions of said generally cylindrical single crystal LuAP scintillating material being exposed directly to a downhole operational environment within a well hole;
an electron multiplier operably connected to said one end of said single crystal LuAP scintillating material and said photocathode downstream of said photocathode;
said one end of said single crystal LuAP scintillating material and said photocathode being oriented toward said electron multiplier;
a metal flange assembly hermetically sealed to said generally cylindrical single crystal LuAP scintillating material and said metal flange assembly being joined to said electron multiplier to form a vacuum enclosure about said electron multiplier downstream of said generally cylindrical single crystal LuAP scintillating material and said photocathode wherein the LuAP crystal forms a physical part of the vacuum enclosure of the electron multiplier; and
said high temperatures being greater than or equal to 125° C.