8.1 IN-CORE COUNTING SYSTEM

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The range of the in-core counting system is from approximately 10 nv to 10 nv (see Figure 1-1 in Section I), Since the counter has a zero gamma sensitivity of approximately

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1 x 10 counts/sec per nv. 100 counts/sec are available at a zero gamma startup,* which pro­vides excellent statistics and a three-decade upscale indication. Pulse overlap becomes large

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above 10 counts/sec, thus limiting the range of the system at this level. The detector can be

retracted at this point to lower fluxes to continue power coverage, but since adequate overlap with the Campbell channel exists, this is not necessary. An integral bias curve for the system at zero gamma is shown in Figure 6-8 of Section VT.