A random walk approach to estimate the confinement of α-particle emitters in nanoparticles for targeted radionuclide therapy

EJNMMI Radiopharmacy and Chemistry

Table 2 Properties of the α-particle emissions in the decay chain of ²²⁵Ac: The physical half-life of the decay T_1/2, the kinetic energies of the emitted α-particles E_α and of therecoiling daughter nuclides E_r are compiled

Mother radio-nuclide	T_1/2	Daughter radio-nuclide	Energy of α-part. E_α in keV	Energy of recoiling daughter nuclide E_rin keV	Range of recoiling daughter nuclides R_r in nm
Mother radio-nuclide	T_1/2	Daughter radio-nuclide	Energy of α-part. E_α in keV	Energy of recoiling daughter nuclide E_rin keV	water	amor-phous silica	graphite	zeolite	gold
²³⁰U	20.8 d	²²⁶Th	5888.4	104.2	85	46	39	42	10.6
²²⁶Th	31 m	²²²Ra	6336.8	114.2	89	48	38	42	11.3
²²⁵Ac	10 d	²²¹Fr	5830.0	105.5	86	47	44	43	10.8
²²¹Fr	4.9 min	²¹⁷At	6341.0	116.9	92	50	47	43	11.7
²¹⁷At	32 ms	²¹³Bi	7066.9	132.7	101	55	52	47	12.9
²²³Ra	11.4 d	²¹⁹Rn	5871.3	107.2	91	47	41.5	36	10.9
²¹⁹Rn	3.96 s	²¹⁵Po	6819.1	126.9	96.5	52	44	45.5	12.4
²¹⁵Po	1.78 ms	²¹¹Pb	7386.2	140.0	104.5	57	48	49.5	13.5
²²⁴Ra	3.68 d	²²⁰Rn	5685.7	103.4	84.5	46	38	40	10.7
²²⁰Rn	55.6 s	²¹⁶Po	6288.1	116.4	91.5	49.5	41.5	43	11.7
²¹⁶Po	0.145 s	²¹²Pb	6778.3	127.9	99	53.5	45	47	12.7

The α-particle energies and half-lifes T_1/2 were retrievd from J. Magill, G. Pfennig, J. Galy (2006) Karlsruher Nuklidkarte, 7th ed.; Haberbeck GmbH, Germany. The range of the recoils in water, amorphous silica, graphite, zeolite and gold were determined using the simulation software SRIM (Ziegler et al., 2013)