Organ dose conversion coefficients for external neutron irradiation based on the Chinese mathematical phantom (CMP)

Figures & data

Figure 1. Shape of the Chinese mathematical phantom.

Table 1. Height and weight of the phantoms compared in this work

Phantom	Height (cm)	Weight (kg)
CMP	170.0	60.0
MIRD phantom (male)	178.6	72.1
VCH	166.0	54.0

Table 2. The cross-section library of neutron used for calculation in this work.

Element	Atomic number	Material identification	Cross-section library	Source	Evaluation date	Emax(MeV)	T(K)	Number of energy points
H	1	1001.24c	la150n	B-VI.6	1998	150	293.6	686
C	6	6000.24c	la150n	B-VI.6	1996	150	293.6	1267
N	7	7014.24c	la150n	B-VI.6	1997	150	293.6	1824
O	8	8016.24c	la150n	B-VI.6	1996	150	293.6	1935
Na	11	11023.60c	endf60	B-VI.1	1977	20	293.6	2543
Mg	12	12000.60c	endf60	B-VI.0	1978	20	293.6	2525
P	15	15031.24c	la150n	B-VI.6	1997	150	293.6	990
S	16	16000.60c	endf60	B-VI.0	1979	20	293.6	8382
Cl	17	17000.60c	endf60	B-VI.0	1967	20	293.6	1816
Ar	18	18000.59c	misc5xs	LANL/T	1982	20	293.6	252
K	19	19000.60c	endf60	B-VI.0	1974	20	293.6	1767
Ca	20	20000.24c	la150n	B-VI.6	1997	150	293.6	4470
Fe	26	26000.55c	rmccs	LANL/T	1986	20	293.6	6899
I	53	53127.60c	endf60	LANL/T	1991	30	293.6	7888

Table 3. Fluence-to-dose conversion coefficients (pGy cm²) for thyroid of CMP under various geometries with the statistical error percentages given in parentheses

En(MeV)	AP	PA	RLAT	LLAT	ROT	ISO
1.E-09	1.96(2.89%)	0.46(6.16%)	0.74(3.35%)	0.75(3.40%)	1.11(3.20%)	1.00(5.11%)
1.E-08	2.64(2.53%)	0.64(5.20%)	1.00(2.91%)	0.99(2.90%)	1.33(2.82%)	1.13(6.27%)
1.E-07	2.87(2.46%)	0.92(4.31%)	1.24(2.65%)	1.24(2.63%)	1.61(2.59%)	1.32(2.36%)
1.E-06	2.78(2.54%)	1.01(4.29%)	1.29(2.57%)	1.29(2.61%)	1.69(2.56%)	1.33(4.04%)
1.E-05	2.55(2.65%)	1.04(4.16%)	1.20(2.69%)	1.20(2.69%)	1.59(2.68%)	1.41(4.27%)
1.E-04	2.26(2.88%)	1.09(4.28%)	1.12(2.84%)	1.10(2.80%)	1.51(2.80%)	1.20(4.32%)
1.E-03	2.16(2.85%)	0.97(4.34%)	1.04(2.89%)	1.07(2.89%)	1.35(2.85%)	1.09(4.52%)
1.E-02	2.60(2.36%)	0.97(4.38%)	1.26(2.44%)	1.21(2.48%)	1.58(2.49%)	1.25(4.04%)
1.E-01	7.40(1.26%)	1.11(4.06%)	3.22(1.41%)	3.21(1.41%)	3.67(1.44%)	2.63(2.51%)
1.E+00	30.90(1.15%)	2.46(3.25%)	15.9(1.29%)	15.88(1.29%)	16.85(1.27%)	11.45(2.18%)
1.E+01	72.75(1.14%)	40.56(1.46%)	61.87(1.16%)	62.01(1.16%)	60.12(1.05%)	47.51(1.68%)
1.E+02	89.01(1.18%)	73.37(1.29%)	87.35(1.11%)	85.53(1.13%)	86.22(1.15%)	85.46(1.23%)

Figure 2. Fluence-to-absorbed dose conversion coefficients for stomach depending on neutron energy under various geometries.

Figure 3. Comparison of fluence-to-absorbed dose conversion coefficients from ICRP 74, the VCH phantom, and CMP for lung and bladder under AP and PA irradiation geometry.

Figure 4. Comparison of fluence-to-absorbed dose conversion coefficients from ICRP 74, the VCH phantom, and CMP for rectum and liver under LLAT and RLAT irradiation geometry.

Figure 5. Comparison of fluence-to-absorbed dose conversion coefficients from ICRP 74, the VCH phantom, and CMP for bone surface and skin under ROT and ISO irradiation geometry.