5.2.6. Elastic scatterings, total cross sections, and reaction cross sections

Table 5.2.69 ielas

Value	Explanation
(D=2)	Elastic scattering option.
=0	Exclude elastic scattering.
=1	Include neutron elastic scattering.
=2	Include neutron and proton elastic scattering.

Table 5.2.70 ielms

Value	Explanation
(D=720)	Number of angle groups for elastic scattering.

Table 5.2.71 icxnp

Value	Explanation
(D=1)	Options for neutron-hydrogen scattering cross sections below 1 GeV.
=0	Original database included in JAM.
=1	Data included in JENDL/HE-2007.

Table 5.2.72 icxsni

Value	Explanation
(D=0)	Options for inelastic scattering, elastic scattering, and total cross sections for nucleon-nucleus collisions.
=0	Pearlstein-Niita’s formula. [1]
=1	KUROTAMA model.
=2	Sato’s formula. [2]

[1]

Improved model based on the formulas shown in the reference [S. Pearlstein, Astrophys. J. 346, 1049 (1989)].

[2]

T. Sato, R. Kataoka, H. Yasuda, S. Yashiro, T. Kuwabara, D. Shiota, and Y. Kubo, Radiat. Prot. Dosim. 161 (2014) 274-278.

Table 5.2.73 icrhi

Value	Explanation
(D=2)	Options for total cross section of nucleus-nucleus collisions.
=0	Shen formula.
=1	Tripathi formula (NASA formula).
=2	KUROTAMA model.
=3	Special model for deuteron.
=4	Tripathi formula optimized.
=5	KUROTAMA model optimized.

In the original NASA formula [3] , a low-energy multiplier, \(X_m\) , is introduced for calculating light-ion cross sections. However, we regard \(X_m=1\) in PHITS.

In the special deuteron model with icrhi=3 , the model has been tuned to reproduce experimental data. Basically, the Tripathi formula is used, while the Shen formula is applied only for carbon targets.

The KUROTAMA model and the KUROTAMA optimized model cover a wide energy range of projectiles in nucleon-nucleus and nucleus-nucleus reaction cross sections. See paper [4] or [5] for more details, respectively. In addition, if you use results obtained from these models in papers or presentations, please be sure to cite the relevant references.

[3]

K. Iida, A. Kohama, and K. Oyamatsu, J. Phys. Soc. Japan 76, 044201 (2007), and L. Sihver et al., Nucl. Instr. & Meth. B 334, 34-39 (2014).

[4]

R.K. Tripathi, F.A. Cucinotta, and J.W. Wilson, Nuclear Instruments and Methods in Physics Research B 155 (1999) 349-356

[5]

Luoni, et al., New J. Phys. 25 (2023) 123024.

Table 5.2.74 icrdm

Value	Explanation
(D=0)	Options for total reaction cross sections for deuteron-induced reactions.
=0	Same as icrhi.
=1	MWO formula.

In the icrdm=1 setting, the MWO formula reproduces reaction cross sections of deuteron-induced reactions for incident energies below 1 GeV, and for target nuclei no lighter than C-12. See the reference [6] for more details; please cite this document in published results based the MWO model.

[6]

K. Minomo, K. Washiyama, and K. Ogata, J. Nucl. Sci. Technol. 54, 127-130 (2017).

Table 5.2.75 icxspi

Value	Explanation
(D=1)	Options for total reaction cross sections for pion-induced reactions.
=0	Geometrical formula.
=1	Hashimoto’s formula.

For the icxspi setting, the Hashimoto’s formula has been used as the default model for calculating pion-induced reaction cross sections since version 2.86. This is an empirical formula that reproduces cross section experimental data better than the geometrical formula specified by icxspi=0.