Neutrons from projectile fragmentation at 600 MeV/nucleon
Journal article, 2023

The neutron emission in projectile fragmentation at relativistic energies was studied with the Large-Area-Neutron-Detector LAND coupled to the ALADIN forward spectrometer at the GSI Schwerionen-Synchrotron (SIS). Stable Sn124 and radioactive Sn107 and La124 beams with an incident energy of 600 MeV/nucleon were used to explore the N/Z dependence of the identified neutron source. A cluster-recognition algorithm is applied for identifying individual particles within the hit distributions registered with LAND. The obtained momentum distributions are extrapolated over the full phase space occupied by the neutrons from the projectile-spectator source. The mean multiplicities of spectator neutrons reach values of up to about 11 and depend strongly on the isotopic composition of the projectile. An effective source temperature of T≈2-5 MeV, monotonically increasing with decreasing impact parameter, is deduced from the transverse momentum distributions. For the interpretation of the data, calculations with the statistical multifragmentation model were performed. The variety of excited projectile spectators assumed to decay statistically is represented by an ensemble of excited sources with parameters determined previously from the fragment production observed in the same experiments. The obtained agreement is very satisfactory for more peripheral collisions where, according to the model, neutrons are mainly emitted during the secondary decays of excited fragments. The neutron multiplicity in more central collisions is underestimated, indicating that other sources besides the modeled statistical breakup contribute to the observed neutron yield. The choice made for the symmetry-term coefficient of the liquid-drop description of produced fragments has a weak effect on the predicted neutron multiplicities.

Author

P. Pawłowski

Polish Academy of Sciences

J. Brzychczyk

Jagiellonian University in Kraków

N. Buyukcizmeci

Selçuk University

Håkan T Johansson

Chalmers, Physics, Subatomic, High Energy and Plasma Physics

W. Trautmann

Helmholtz Association of German Research Centres

A. Wieloch

Jagiellonian University in Kraków

P. Adrich

Narodowe Centrum Badan Jadrowych

T. Aumann

Helmholtz Association of German Research Centres

T. Barczyk

Jagiellonian University in Kraków

S. Bianchin

Helmholtz Association of German Research Centres

K. Boretzky

Helmholtz Association of German Research Centres

Alexander Botvina

Helmholtz Association of German Research Centres

Goethe University Frankfurt

A. Chbihi

Grand Accélérateur National d'Ions Lourds (GANIL)

J. Cibor

Polish Academy of Sciences

B. Czech

Polish Academy of Sciences

H. Emling

Helmholtz Association of German Research Centres

J. D. Frankland

Grand Accélérateur National d'Ions Lourds (GANIL)

M. Heil

Helmholtz Association of German Research Centres

A. Le Fèvre

Helmholtz Association of German Research Centres

Y. Leifels

Helmholtz Association of German Research Centres

J. Lühning

Helmholtz Association of German Research Centres

J. Łukasik

Polish Academy of Sciences

Helmholtz Association of German Research Centres

U. Lynen

Helmholtz Association of German Research Centres

Z. Majka

Jagiellonian University in Kraków

I. N. Mishustin

Frankfurt Institute for Advanced Studies

W. F.J. Müller

Helmholtz Association of German Research Centres

R. Ogul

Selçuk University

H. Orth

Helmholtz Association of German Research Centres

R. Palit

Helmholtz Association of German Research Centres

D. Rossi

Helmholtz Association of German Research Centres

C. Schwarz

Helmholtz Association of German Research Centres

C. Sfienti

Johannes Gutenberg University Mainz

H. Simon

Helmholtz Association of German Research Centres

K. Summerer

Helmholtz Association of German Research Centres

H. Weick

Helmholtz Association of German Research Centres

B. Zwiegliński

Narodowe Centrum Badan Jadrowych

Physical Review C

24699985 (ISSN) 24699993 (eISSN)

Vol. 108 4 044610

Atomic nuclei that merely exist

Swedish Research Council (VR) (2022-04248), 2023-01-01 -- 2026-12-31.

Subject Categories (SSIF 2011)

Subatomic Physics

DOI

10.1103/PhysRevC.108.044610

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4/3/2025 1