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In this article, we present a measurement of flow rate, yield and effusion time of a $^{23}$Ne production and transport system. We used an accelerator-driven Li(d,n) neutron source to produce neutrons up to 20 MeV. The radioactive atoms were produced by a $^{23}$Na(n,p) reaction at a NaCl target. Later, the atoms were diffused out from the NaCl crystals and effused from the production chamber via a 10 m hose to a measurement cell and their decay products were detected using high purity germanium (HPGe) and plastic scintillator detectors. The resulting flow rate was $6.9\pm0.5\cdot 10^4\sfrac{atoms}{sec}$ and the total yield was $3.2\pm0.4\cdot10^{-9}\sfrac{atoms}{deuteron}$. We summarize our methods and estimates of efficiencies, rates of production and effusion.

We review the current status of the radioisotopes program at the Soreq Applied Research Accelerator Facility (SARAF), where we utilize an electrostatic-ion-beam trap and a magneto-optical trap for studying the nuclear $\beta$-decay from trapped radioactive atoms and ions. The differential energy spectra of $\beta$'s and recoil ions emerging from the decay is sensitive to beyond standard model interactions and is complementary to high energy searches. The completed facility SARAF-II will be one of the world's most powerful deuteron, proton and fast neutron sources, producing light radioactive isotopes in unprecedented amounts, needed for obtaining enough statistics for a high precision measurement.

The Soreq Applied Research Accelerator Facility (SARAF) is under construction in the Soreq Nuclear Research Center at Yavne, Israel. When completed at the beginning of the next decade, SARAF will be a user facility for basic and applied nuclear physics, based on a 40 MeV, 5 mA CW proton/deuteron superconducting linear accelerator. Phase I of SARAF (SARAF-I, 4 MeV, 2 mA CW protons, 5 MeV 1 mA CW deuterons) is already in operation, generating scientific results in several fields of interest. The main ongoing program at SARAF-I is the production of 30 keV neutrons and measurement of Maxwellian Averaged Cross Sections (MACS), important for the astrophysical s-process. The world leading Maxwellian epithermal neutron yield at SARAF-I ($5\times 10^{10}$ epithermal neutrons/sec), generated by a novel Liquid-Lithium Target (LiLiT), enables improved precision of known MACSs, and new measurements of low-abundance and radioactive isotopes. Research plans for SARAF-II span several disciplines: Precision studies of beyond-Standard-Model effects by trapping light exotic radioisotopes, such as $^6$He, $^8$Li and $^{18,19,23}$Ne, in unprecedented amounts (including meaningful studies already at SARAF-I); extended nuclear astrophysics research with higher energy neutrons, including generation and studies of exotic neutron-rich isotopes relevant to the rapid (r-) process; nuclear structure of exotic isotopes; high energy neutron cross sections for basic nuclear physics and material science research, including neutron induced radiation damage; neutron based imaging and therapy; and novel radiopharmaceuticals development and production. In this paper we present a technical overview of SARAF-I and II, including a description of the accelerator and its irradiation targets; a survey of existing research programs at SARAF-I; and the research potential at the completed facility (SARAF-II)., Comment: 32 pages, 31 figures, 10 tables, submitted as an invited review to European Physics Journal A

We study Mode I crack propagation in amorphous material via a molecular dynamics simulation of a binary alloy with pairwise central-force interactions. We find that when the system is subjected to constant displacement after introduction of a seed crack, the crack does not propagate. This was found to be true both for the modified Lennard-Jones potential of Falk and a shorter-range potential of our own devising. Crystalline samples prepared with these potentials exhibit normal brittle fracture, with running cracks. Only when subjected to a constantly increasing strain did the crack in the glasses lengthen. Even here, once the strain stopped increasing, the crack tip stopped moving. We examined the stress-strain curve for our model materials, and found that they did not exhibit the saturated stress plateau characteristic of ductile materials. We attribute the failure of crack propagation in this system to the availability of many meta-stable configurations available to the crack tip which serve to soak up the energy which would otherwise drive the crack. We conclude that this class of models is inadequate to describe crack propagation in brittle glasses.