Results are presented from spectroscopic studies of a composite Z-pinch in
the Angara-5-1 device. A load that was used to create the composite Z-pinch
consisting of an outer annular gas (argon or propane) shell and a solid in
ner cylinder (fiber) made from a foamlike material (agar-agar with the addi
tion of KCI or NaCl) with an initial density of similar to 10(-2) g/cm(3).
Zn experiments, the intensity of line emission was measured for various she
ll compositions and for the shell mass per unit length from 3 to 60 mu g/cm
. The fiber mass per unit length varied from 55 to 80 mu g/cm, and the weig
ht content of salt additives varied from 30 to 57%. The measurements show t
hat the temperature of a substantial fraction of the fiber material is comp
arable with the shell temperature. During compression, the electron density
and electron temperature of the pinch (gas-jet and fiber) plasma reaches v
alues of n(e) approximate to 10(21) cm(3) and T-e approximate to 1 keV, res
pectively. The spatially resolved spectroscopy shows that luminous regions
of the gas-jet and fiber ions coincide with each other and occupy at most o
ne-half of the pinch length (about 5 mm for Ar ions and 3-4 mm for K and CI
ions). The measurements of the electron temperature near the cathode (simi
lar to 500 eV, which is lower than the electron temperature in the central
part of the pinch) show the presence of a temperature gradient along the pi
nch axis. Possible mechanisms for fiber heating are discussed.