A Study of the Elastic Scattering of 2 to 3 MeV Neutrons by 40Ca and 32S Using an Associated Particle Time of Flight Spectrometer
An associated particle time of flight spectrometer based on the D(d,n)3He reaction has been developed using thin deuterated polythene targets. The competing D(d,p)3T was used to monitor the neutron output. The spectrometer has been used to study the elastic scattering of a 2 - 3 MeV neutrons in 40Ca and 32S; in each case the differential elastic scattering cross sections have been measured. In the angular range 20° - 100° in the laboratory frame of reference the results have been compared with an optical model analysis. Values of ¿2 per point of 3.46 and 2.84 for 40C and 32S respectively were obtained.
Nuclear Data Sheets for A=40☆
Abstract Nuclear spectroscopic information for the known nuclides of mass 40 (Al,Si,P,S,Cl,Ar,K,Ca,Sc,Ti) has been evaluated. The principal sources of the adopted levels presented are Endt's evaluations (1990En08, 1978En02). The data sets for reactions and decays, including all available gamma-ray data, are based mostly on the original literature. There are no data available for the excited states in 40Al, 40Si, 40P and 40Ti. The identification and particle stability of 40Mg are still uncertain, although search for this nuclide has been made (2002Lu09,2002No11,2003Pe31).
Pedagogy of the “Not”: Negation, Exodus, and Postdigital Temporal Regimes
Postdigital capitalist time is an incessant acceleration that acts to homogenize time and wed us to the present, to which we have to constantly catch up. While the impulse of this is no doubt economic (the realization of value), it is crucially undergirded by a pedagogical logic wherein we have to perpetually learn and re-learn the latest apps, social media configurations, operating systems, and so on. Political strategies of resistance thus need to be bolstered by an alternative mode of educational life, and I propose a pedagogy of the “not” as one possibility. Such a pedagogy is an act of suspension that sustains a detachment from the present, clearing out oppositions and thereby exposing us to a radical indeterminacy and potentiality that is always untimely. Suspension is the praxis of negation, which means that negation operates by keeping sense indeterminate to meaning and signification. Rather than suppressing, disavowing, or annihilating the stated content, negation retains even that which is negated. While this would appear as a form of exopedagogy, which withdraws from the dialectic of the private/public, I instead argue that it redefines the terms of any dialectic, redefining the very categories exopedagogy withdraws from. Before concluding, I spend some time with Sandy Grande’s important critiques of Eurocentrism and progress in Western critical education, demonstrating how negation as suspension circumvents these errors through its accommodation of—or, better, insistence on—variegated temporalities and forms of life.