A review of the dense Z-pinch

More documents

Recommendations

Info

Plasma Phys. Control. Fusion 53 (2011) 093001 Topical Review Figure 43. X-ray images of the plasma column as stagnation is reached using a nested W wire array on Z at Sandia. The large format x-ray pinhole data from shot 665 has 2 sets of filters, (a) to (e) 4.8 µm Kimfoil and 193 Å Al and (f) to (i) the Al filter is increased to 1313 Å. The times are (a) −6.6 ns, (b) and (f) −4.6 ns (c) and (g) −1.1 ns, (d) and (h) +0.2 ns, and (e) and (i) +2.4 ns relative to peak x-ray emission. The authors identify bubble regions labelled b1, b2, b3. Reprinted figure with permission from [323]. Copyright 2005 by the American Physical Society. 73
Plasma Phys. Control. Fusion 53 (2011) 093001 Topical Review Figure 44. Scheme of the experimental set-up for x-ray backlighting by image of a 20 µm Ti wire in a 16 wire array at 180 ns on MAGPIE. Reprinted with permission from [578]. Copyright 2001, American Institute of Physics. Figure 45. Electron pressure versus density for various temperatures in a modified Thomas–Fermi model. A typical trajectory for material ablated from the core and expanding into the corona is shown. Reprinted figure with permission from [336]. Copyright 2000 by the American Physical Society. the wire induces a breakdown in the vapour (and desorbed gases) surrounding the wire core. There is a sharp voltage drop as the current transfers to the highly conducting plasma. Further experiments by Sinars et al measured the initial energy deposition and expansion rates of exploding wires [334]. Recently Douglass et al [335] employed multi-frame radiography to show the development of structure in wire cores. This heterogeneous core structure has not been modelled and makes realistic calculations of mass ablation rates very difficult. So far the expanding cores are assumed to be in a homogeneous state, being a modified Thomas–Fermi equation of state as shown in figure 45 and used by Chittenden et al [336]. Here single wire ‘cold-start’ 2D simulations showed a persistent core surrounded by a m = 0 unstable coronal plasma in the r–z plane, showing excellent agreement with coronal measurements in experiments by Beg et al [254]. Expansion rates and coronal plasma formation have recently been studied by Shelkovenko et al [337]. A paper by Yu et al [338] shows that radiation transport is greater than thermal transport in most of the dense plasma surrounding the wire core. Yu employs r-ϑ simulations of a wire in an array to obtain the mass ablation rate in an asymptotic steady state, using a single-group radiation diffusion model. To gain physical insight and to obtain analytic scaling laws Yu 74
Page 1 and 2:
Home Search Collections Journals Ab
Page 3 and 4:
Plasma Phys. Control. Fusion 53 (20
Page 5 and 6:
Page 7 and 8:
Page 9 and 10:
Page 11 and 12:
Page 13 and 14:
Page 15 and 16:
Page 17 and 18:
Page 19 and 20:
Page 21 and 22:
Page 23 and 24: Plasma Phys. Control. Fusion 53 (20
Page 73: Plasma Phys. Control. Fusion 53 (20
Page 125 and 126:
Page 127 and 128:
Page 129 and 130:
Page 131 and 132:
Page 133 and 134:
Page 135 and 136:
Page 137 and 138:
Page 139 and 140:
Page 141 and 142:
Page 143 and 144:
Page 145 and 146:
Page 147 and 148:
Page 149 and 150:
Page 151 and 152:
Page 153 and 154:
Page 155 and 156:
Page 157 and 158:
Page 159 and 160:
Page 161 and 162:
Page 163 and 164:
Page 165 and 166:
Page 167 and 168:
Page 169:
show all

A review of the dense Z-pinch

Create successful ePaper yourself

Delete template?

Save as template?