An improved Feynman-α analysis with a moving–bunching technique

Figures & data

Figure 1. Illustration of the conventional bunching procedure.

Figure 2. Illustration of the present bunching procedure.

Figure 3. Reactor configuration and detector location.

Table 1. Control rod patterns employed in the present experiment.

	Rod position				Reactivity
Pattern	Safety #1	Safety #2	Shim	Regulating	[%Δk/k]
A	U.L.	U.L.	L.L.	U.L.	−0.368
D	L.L.	L.L.	L.L.	L.L.	−1.672

Note: L.L. – lower limit, U.L. – upper limit.

Figure 4. Applicability of different bunching techniques to time-sequence data detected by a neutron counter far from the core at rod pattern A: (a) conventional bunching technique applied; (b) moving–bunching technique applied.

Figure 5. Applicability of different bunching techniques to time-sequence data detected by a neutron counter far from core at rod pattern D: (a) conventional bunching technique applied; (b) moving–bunching technique applied.

Figure 6. Applicability of different bunching techniques to time-sequence data detected by a neutron counter close to core at rod pattern D: (a) conventional bunching technique applied; (b) moving–bunching technique applied.

Table 2. Prompt-neutron decay constant obtained by Feynman-α analysis [1/s].

	Conventional bunching technique			Present bunching technique
Rod Pattern	Counter #1	Counter #2	Counter #3	Counter #1	Counter #2	Counter #3
A	67.1 ± 0.7	71.4 ± 1.1	Failed	66.6 ± 0.2	64.8 ± 0.4	63.5 ± 7.5
D	153.6 ± 4.9	144.6 ± 8.1	Failed	154.2 ± 1.9	151.1 ± 3.0	192.6 ± 93.9

Figure A1. Filtering over (2M + 1) gates.