skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


  • Home
  • Search Results
  • Page 1 of 1

Search for: All records

Creators/Authors contains: "Callahan, L"

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. ; ; ; ; ; ; ; (, Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms)
    Full Text Available 
  2. ; ; ; ; ; ; ; ; ; ; et al (, The Astrophysical Journal)
    Abstract Neutron-induced nuclear reactions play an important role in the Big Bang Nucleosynthesis. Their excitation functions are, from an experimental point of view, usually difficult to measure. Nevertheless, in the last decades, big efforts have led to a better understanding of their role in the primordial nucleosynthesis network. In this work, we apply the Trojan Horse Method to extract the cross section at astrophysical energies for the3He(n,p)3H reaction after a detailed study of the2H(3He,pt)H three-body process. Data extracted from the present measurement are compared with other published sets. The reaction rate is also calculated, and the impact on the Big Bang nucleosynthesis is examined in detail. 
    more » « less
    Full Text Available 
  3. ; ; ; ; ; ; ; ; ; ; et al (, EPJ Web of Conferences)
    Mattoon, C.M.; Vogt, R.; Escher, J.; Thompson, I. (Ed.)
    The cross-section of the thermal neutron capture41Ar(n,γ)42Ar(t1/2=32.9 y) reaction was measured by irradiating a40Ar sample at the high-flux reactor of Institut Laue-Langevin (ILL) Grenoble, France. The signature of the two-neutron capture has been observed by measuring the growth curve and identifying the 1524.6 keV γ-lines of the shorter-lived42K(12.4 h) β−daughter of42Ar. Our preliminary value of the41Ar(n,γ)42Ar thermal cross section is 240(80) mb at 25.3 meV. For the first time, direct counting of42Ar was performed using the ultra-high sensitivity technique of noble gas accelerator mass spectrometry (NOGAMS) at Argonne National Laboratory, USA. 
    more » « less
    Full Text Available 
  4. ; ; ; ; ; ; ; ; ; ; et al (, EPJ Web of Conferences)
    Freeman, S.; Lederer-Woods, C.; Manna, A.; Mengoni, A. (Ed.)
    The thermodynamical conditions and the neutron density produced in a laser-induced implosion of a deuterium-tritium (DT) filled capsule at the National Ignition Facility (NIF) are the closest laboratory analog of stellar conditions. We plan to investigate neutron-induced reactions on 40 Ar, namely the 40 Ar( n , 2 n ) 39 Ar( t 1/2 =268 y), the 40 Ar( n , γ) 41 Ar(110 min) and the potential rapid two-neutron capture reaction 40 Ar(2 n , γ) 42 Ar(33 y) in an Ar-loaded DT capsule. The chemical inertness of noble gas Ar enables reliable collection of the reaction products. 
    more » « less
    Full Text Available 
  5. ; ; ; ; ; ; ; (, Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms)
    null (Ed.)
    Full Text Available 
  6. ; ; ; ; ; ; ; ; ; ; et al (, Journal of Physics: Conference Series)
    null (Ed.)
    Full Text Available 
  7. ; ; ; ; ; ; ; ; ; ; et al (, The European Physical Journal A)
    Full Text Available 
  8. ; ; ; ; ; ; ; ; ; ; et al (, EPJ Web of Conferences)
    In the network of reactions present in the Big Bang nucleosynthesis, the 3 He(n, p) 3 H has an important role which impacts the final 7 Li abundance. The Trojan Horse Method (THM) has been applied to the 3 He(d, pt)H reaction in order to extract the astrophysical S(E)-factor of the 3 He(n, p ) 3 H in the Gamow energy range. The experiment will be described in the present work together with the first preliminary results. 
    more » « less
    Full Text Available