公开(公告)号：US3539910A

公开(公告)日：1970-11-10

申请号：US3539910D

申请日：1968-10-29

Applicant: SCHLUMBERGER TECHNOLOGY CORP

Inventor： HENRY LOUIS ,  SEEMAN BRONISLAV

IPC: G01V3/18 ,  G01V3/24

CPC classification number: G01V3/24 ,  G01V3/18

公开(公告)号：US3900731A

公开(公告)日：1975-08-19

申请号：US32619773

申请日：1973-01-22

Applicant: SCHLUMBERGER TECHNOLOGY CORP

Inventor： CHEVALIER PHILIPPE ,  SEEMAN BRONISLAV

IPC: H01J43/08 ,  G01J1/42 ,  G01T1/164 ,  G01T1/20 ,  G01T1/208 ,  G01T1/40 ,  H01J43/30 ,  H03G3/20 ,  H01J39/12

CPC classification number: G01T1/40 ,  G01T1/208 ,  H01J43/30

Abstract: A photomultiplier gain stabilization system maintains the mean output current of a photomultiplier at a constant level by compensating its variations through a modification of the illumination of its photocathode. The photocathode is coupled to a photoemissive diode, supplied with a current representative of the difference between the value of the mean current of the photomultiplier anode and a reference current value equal to at least the maximum value of the anode current.

公开(公告)号：US3922541A

公开(公告)日：1975-11-25

申请号：US42711073

申请日：1973-12-21

Applicant: SCHLUMBERGER TECHNOLOGY CORP

Inventor： SEEMAN BRONISLAV

IPC: G01T1/40 ,  G01V5/12 ,  G01V5/00 ,  G01T1/20

CPC classification number: G01V5/12 ,  G01T1/40

Abstract: In accordance with an illustrative embodiment of the present invention, a technique for stabilizing the gain of a radiation detector is described. In this technique, a reference radiation source having a predetermined energy spectrum is located adjacent, or enclosed within, a scintillator of a radiation detector. Those signals produced by the radiation detector which represent energies within an energy range defined by the reference source energy spectrum are selected and used to determine the relationship between the energy spectrum of the reference source and the energy spectrum of the selected detector signals. From this relationship, a reference signal is generated which is used to adjust the radiation detector gain in a nonlinear manner to cause the energy spectrum of the selected radiation detector signals to correspond to that of the reference radiation source.

Abstract translation: 根据本发明的说明性实施例，描述了一种用于稳定放射线检测器的增益的技术。 在该技术中，具有预定能谱的参考辐射源位于辐射探测器的闪烁体附近或封闭在其内。 由辐射检测器产生的表示由参考源能谱限定的能量范围内的能量的那些信号被选择并用于确定参考源的能谱与所选择的检测器信号的能谱之间的关系。 根据该关系，产生用于以非线性方式调节辐射探测器增益的参考信号，以使所选择的辐射检测器信号的能谱对应于参考辐射源的能谱。

公开(公告)号：US3900733A

公开(公告)日：1975-08-19

申请号：US32637973

申请日：1973-01-24

Applicant: SCHLUMBERGER TECHNOLOGY CORP

Inventor： SEEMAN BRONISLAV

IPC: G01V5/04 ,  G01V5/12 ,  H01J43/30 ,  G01V5/00

CPC classification number: H01J43/30 ,  G01V5/04 ,  G01V5/125

Abstract: In a tool for measuring the density of the geological formations traversed by a borehole, an apparatus corrects the effects of barite on the count rate of the pulses which are used for the density measurement and have an amplitude higher than a given threshold, by determining the deformations in the amplitude spectrum of these pulses and adjusting this threshold so as to compensate by the variation in the number of pulses taken into account, resulting from the adjustment, for the variation in the number of counted pulses resulting from the said deformations.