Documentation on the ACTI Libraries

Released: 2000-07-20

ACTI is a continuous-energy neutron data library compatible with MCNP versions 4C and later. It is based on ENDF/B-VI Release 8 evaluations that incorporated improvements to the photon-production data for radiative capture at thermal energies. The evaluation improvements were based on a compilation of the best experimental data for thermal-neutron capture for the naturally occurring isotopes for

• elements from H through Zn
• ^{182,183,184,186}W
• ^{70,72,73,74,76}Ge (no ENDF modifications made)
• ¹⁴⁹Sm (no ENDF modifications made)
• ^155,157Gd (no ENDF modifications made)
• ¹⁸¹Ta (no ENDF modifications made)

ENDF evaluations were updated for

• Z=1-10: ¹H, ⁴He, ⁹Be, ¹⁴N, ¹⁶O, ¹⁹F,
• Z=11-20: Na, Mg, ²⁷Al, ³²S, S, ^35,37Cl, K, Ca,
• Z=21-30: ⁴⁵Sc, Ti, ⁵¹V, ^50,52,53,54Cr, ⁵⁵Mn, ^54,56,57,58Fe, ^{58,60,61,62,64}Ni, ^63,65Cu
• Z>30: ^{182,183,184,186}W

In addition, the inelastic cross sections and corresponding secondary-photon distributions were updated for ¹⁶O. Complete new evaluations were submitted to ENDF for ^35,37Cl. Data from the ENDF evaluations for ^28-30Si were also included in the ACTI library for completeness. The isotopic silicon evaluations were updated in 1997 and include the latest experimental data for radiative capture.

The ACTIA library contains this data for 297 K, while the ACTIB library contains this data for 77 K and 3000 K

Documentation

1. "ACTI - A MCNP Continuous-Energy Neutron Data Library for Prompt Gamma-Ray Spectroscopy," Frankle, S.C., Reedy, R.C., Young, P.G., LA-UR-02-7783

2. "ACTI - An MCNP Data Library for Prompt Gamma-Ray Spectroscopy," Frankle, S.C., Reedy, R.C., Young, P.G.,(2002) LA-UR-02-1485

3. S. C. Frankle, R. C. Reedy, and P. G. Young, "ACTI – An MCNP Data Library for Prompt Gamma-ray Spectroscopy," Proceedings of the 12th Biennial Radiation Protection and Shielding Topical Meeting, Santa Fe, NM (April 15-19, 2002).

4. "Improved Photon-Production Data for Thermal Neutron Capture in the ENDF/B-VI Evaluations," Frankle, S.C., Reedy, R.C., Young, P.G., (2001) LA-13812

5. "Prompt Gamma Rays from Radiative Capture of Thermal Neutrons by Elements from Hydrogen through Zinc," Atomic Data and Nuclear Data Tables (doi:10.1006/adnd.2001.0870) published electronically Nov. 1, 2001.

6. "Evaluated Database for Prompt Gamma Rays from Radiative Capture of Thermal Neutrons by Elements from Hydrogen to Zinc," IAEA CD-ROM distribution under PGAA (2002).

7. "Improvements to the Photon-Production Data for Radiative Capture in ENDF,” Frankle, S.C., Reedy, R.C., Young, P.G., Madigan, W.P., Appl. Radiat. Isot. 53, 929 (2000).

8. "Neutron Capture Yields for Gamma-Ray Spectroscopy,” Reedy, R.C., Frankle, S.C., Tenth International Symposium on Capture Gamma-Ray Spectroscopy and Related Topics, (1999) (LA-UR-99-3480 and LA-UR-99-4646.)

9. "Improved Photon Production Data for Thermal Neutron Capture in ENDF,” Frankle, S.C., Young, P.G, Tenth International Symposium on Capture Gamma-Ray Spectroscopy and Related Topics, (1999) (LA-UR-99-3994 and LA-UR-99-4669).

10. "Improved Photon Production Data for MCNP,” Adams, A.A., Frankle, S.C., Little, R.C., 1998 Radiation Protection and Shielding Division Topical of American Nuclear Society, LA-UR-97-5176