Fragmentation of relativistic<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi mathvariant="normal">Fe</mml:mi></mml:mrow><mml:mprescripts/><mml:mrow/><mml:mrow><mml:mn>56</mml:mn></mml:mrow><mml:mrow/><mml:mrow/></mml:mmultiscripts></mml:mrow></mml:math>

The fragmentation of $^{56}\mathrm{Fe}$ at 1.88 GeV/nucleon has been studied on H, Li, Be, C, S, Cu, Ag, Ta, Pb, and U targets. The detection apparatus consisted of a simple transmission detector. A method is presented which eliminates the effects of multiple interactions in the targets which were typically half an interaction-length thick. Elemental production cross sections, $\ensuremath{\sigma}(Z)$, were measured for $Z=13 \mathrm{to} 25$. Measured charge-changing cross sections, ${\ensuremath{\sigma}}_{\ensuremath{\Delta}Z\ensuremath{\ge}1}$, and derived mass-changing cross sections, ${\ensuremath{\sigma}}_{\ensuremath{\Delta}A\ensuremath{\ge}1}$, are presented for each target. The $\ensuremath{\sigma}(Z)$ factor into a term which depends only on the target and a term which depends only on the fragment observed. The ${\ensuremath{\sigma}}_{\ensuremath{\Delta}Z\ensuremath{\ge}1}$ and ${\ensuremath{\sigma}}_{\ensuremath{\Delta}A\ensuremath{\ge}1}$ follow a simple geometric behavior. The cross section for the removal of one proton from the $^{56}\mathrm{Fe}$ projectile is enhanced for the heavier targets. This effect is described by a model assuming Coulomb dissociation. The $\ensuremath{\sigma}(Z)$ for $^{56}\mathrm{Fe}$ on the $H$ target are compared to the semiempirical formulas of Silberberg and Tsao.NUCLEAR REACTIONS H($^{56}\mathrm{Fe}$,$S$), Li($^{56}\mathrm{Fe}$,$X$), Be($^{56}\mathrm{Fe}$,$X$), C($^{56}\mathrm{Fe}$,$X$), S($^{56}\mathrm{Fe}$,$X$), Cu($^{56}\mathrm{Fe}$,$X$), Ag($^{56}\mathrm{Fe}$,$X$) Ta($^{56}\mathrm{Fe}$,$X$), Pb($^{56}\mathrm{Fe}$,$X$), U($^{56}\mathrm{Fe}$,$X$), $X=\mathrm{Al}\mathrm{to}\mathrm{Mn}$, measured elemental production cross sections; measured charge-changing cross sections and derived mass changing cross sections. Iron fragmentation cross sections, relativistic heavy ions, thick target corrections, Coulomb dissociation.