Reply to Schimmack: Critique of Cesario et al. (2019)

Abstract

Recently Cesario, Johnson, & Terrill (2019) published a report showing that, when benchmarking on various violent crime rates, there was no evidence of anti-Black disparity in police use of deadly force, at the nationwide level for 2015-2016. In response, Schimmack (2019) criticized several aspects of the methods used by Cesario et al., claiming "Their calculations are purely hypothetical and their conclusions suggest only that their assumptions are wrong." In this reply, Cesario addresses the major and minor points raised by Schimmack, arguing that Schimmack's criticisms misunderstand the original argument and fail to appreciate the nature of fatal police shootings.

Review of recent experimental and modeling advances in the understanding of lower hybrid current drive in ITER-relevant regimes

“…Previous experiments on FTU indicated that SDF would not play a significant role in tokamak experiments performed so far at high plasma densities, since LHCD effects occurred at very high density (n e =2  10 20 m -3 ). With an ITER-relevant n e profile and high T e periphery regime, the RF probe spectrum was symmetrically broadened (up to 7 MHz), attributable to SDF [2]. Conversely, a significantly broadened and downshifted spectrum (up to 15 MHz), not accompanied by any LHCD effect in plasma was produced in standard high-density regime, consistent with PI modelling results [2].…”

“…Recent time dependent ray tracing / Fokker Planck analysis [18] has indicated that loss of wave accessibility at high density in JET could be partially responsible for a reduction in the LHCD effect; however this analysis relies on multiple passes of the LH wavefront between the slow wave cut-off and the confluence layer between the slow and fast wave modes in plasma. However, detailed analysis of spectral broadening via the PI effect has shown that this mechanism is a strong candidate for the decrease in HXR emission since the density at large radii in these discharges exceeds a critical value of  4 x10 19 m -3 , which promotes conditions of cold plasma edge that favours the undesired effect of PI spectral broadening [2,17].…”

“…With an ITER-relevant n e profile and high T e periphery regime, the RF probe spectrum was symmetrically broadened (up to 7 MHz), attributable to SDF [2]. Conversely, a significantly broadened and downshifted spectrum (up to 15 MHz), not accompanied by any LHCD effect in plasma was produced in standard high-density regime, consistent with PI modelling results [2]. Therefore, the cause of the reduction of the LHCD at high density has not been conclusively shown from the FT-U experiments alone.…”

“…The LH star suite of numerical codes [2,30] has been further utilised for calculating the driven current profile. In order to model the deposition profiles, and taking into account the above PI code results, the LH power spectrum broadened by the PI mechanism has been considered as initial spectrum, in place of that launched by the antenna.…”

“…However, how to improve LHCD capability at high density is an important issue to be solved before this application. Experiments on FTU identified a new method that enabled for the first time producing LHCD at densities even higher than in ITER [2]. This method was assessed on the basis of previous theoretical predictions of diminished parasitic effect of spectral broadening due to parametric instability (PI) under higher temperature of plasma edge [3].…”