Introduction

As the centre-of-mass energy of an e⁺e^- collider is increased, measurements of the photon structure function, F₂^$\gamma$, can be extended into two new kinematic regions. A preliminary study [1] has shown that a 500 GeV e⁺e^- linear collider with a luminosity of 10 fb^-1 per year provides sufficient hadronic gamma-gamma events with a tagged electron or positron to give good statistics at both high Q² (10⁴ GeV²) and low Bjorken-x ( 0.001 < x < 0.1). Events at high Q² would allow for the QCD test of the linear rise of F₂^$\gamma$ with logQ². The high statistics at small x presents the possibility of observing whether F₂^$\gamma$ behaves in the same way as the proton structure function i.e. increasing as x decreases. It is also the region in which theoretical predictions of F₂^$\gamma$ differ significantly. However, LEP measurements have since demonstrated that measuring F₂^$\gamma$ at low-x is not trivial [2,3] and requires a good knowledge of the hadronic response of the forward region detectors, in addition to having an electromagnetic calorimeter at small angles for tagging. This is also true of the future e⁺e^- linear collider (LC) detector.