Information about Neptunium-237:


Wikipedia	Neutron Cross Sections	X-Ray Transitions	X-Ray Attenuation

Mass-Energy Data:

Atomic Mass:	237.048167	±	0.000002	amu
Excess Mass (Δ):	44.867501	±	0.001961	MeV
Binding Energy:	1795.277138	±	0.001986	MeV
β^- Decay Energy:	-0.220318	±	0.001298	MeV

"The 1995 update to the atomic mass evaluation" by G.Audi and A.H.Wapstra, Nuclear Physics A595 vol. 4 p.409-480, December 25, 1995.

Radioactive Decay Data:

Spin: 5/2+
Half life: 2144000 years ( 6.76218×10⁺¹³ sec., λ = 1.02504×10^-14 s^-1)
Mode of decay:
α
to
233
91
Pa
(Q = 4.959 MeV)
Mode of decay: SF Branch ratio: <=2E-10 %
Meta state at 2.800 Mev 2144000
Half life: 45 ns ( 4.5×10⁺¹⁰ sec., λ = 1.54033×10^-11 s^-1)
Possible parent nuclides:
β^- from
237
92
U

E.C. from
237
94
Pu

α from
241
95
Am

R.R.Kinsey, et al.,The NUDAT/PCNUDAT Program for Nuclear Data,paper submitted to the 9 th International Symposium of Capture-Gamma_raySpectroscopy and Related Topics, Budapest, Hungary, Octover 1996.Data extracted from NUDAT database (Jan. 14/1999)

Magnetic Dipole Moments and Electric Quadrupole Moments
Ex(kev)	T_1/2	Spin	m(nm)	Q(b)	Ref. Std.	Method	Reference
0	2.1x10*6y	5/2+	+3.14(4)			"EPR, R"	JCP 53 809 (70)
			+~2.9			ME	PR 165 1319 (68)
				+3.866(6) a		"Mu-X, Pi-X, ME"	PL 189B 7 (87)/PR 186 1296 (69)
60	68 ns	5/2-	+1.68(3)		[237Np]	ME	PR 171 316 (68)/JCP 53 809 (70)
			+1.95(15)			TDPAC	NP A104 588 (67)
				+3.85(4)	[237Np]	ME	BAPS 13 28 (68)

N. J. Stone, Table of Nuclear Magnetic Dipole and Electric Quadrupole Moments, to be published. 2000 Courtesy of T. Burrows at BNL/NNDC.