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\@writefile{lof}{\contentsline {figure}{\numberline {3}{\ignorespaces Right: Measurement of the total anti-quark distribution as a function of $Q^2$ for different $x$ by CDHS. Left bottom: Measurement of $R$ derived from the $y$ distribution, compared with SLAC data at different $Q^2$ (open points). Left top: Determination of the sum and differences of the the total quark and total anti-quark distributions and also of the gluon distribution as a function of $x$, at $Q^2 =20$\tmspace  +\thinmuskip {.1667em}GeV$^2$. }}{5}}
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\@writefile{lof}{\contentsline {figure}{\numberline {4}{\ignorespaces Extrapolation of the behaviour of $F_2$ and the gluon distribution $xg$ towards low $x$ at $Q^2=10$ (top) and $Q^2=10^4$\tmspace  +\thinmuskip {.1667em}GeV$^2$ (bottom) within the framework of the 1991 global pdf analysis\nobreakspace  {}\cite  {MT}. The low $x$ behaviour was phenomenologically determined by the term $x^B$, which could be large or small. Both fits described the data which extended down to $x$ about $0.01$ at a few GeV$^2$. From the measurements of HERA one now knows that $F_2$ at $Q^2 =10$\tmspace  +\thinmuskip {.1667em}GeV$^2$ and $x=10^{-4}$ is about $1.7$ and $xg \simeq 13$, thus somewhat closer to the $B_1$ curves. }}{6}}
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\@writefile{lof}{\contentsline {figure}{\numberline {5}{\ignorespaces  The first measurements of H1 (solid points) and ZEUS (open points) of the proton structure function $F_2(x,Q^2)$ based on the data taken in 1992 shown as a function of Bjorken $x$. The HERA experiments were able to extend the kinematic range of the $F_2$ data provided by the fixed target electron (SLAC) and muon (BCDMS, NMC) proton experiments by two orders of magnitude into the then-unknown domain of low $x$. For GRV91 see text.}}{7}}
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\@writefile{lof}{\contentsline {figure}{\numberline {6}{\ignorespaces Left: The first observations of hard diffraction - top left: Distribution in DIS events of $\eta _{max}$, the maximum pseudorapidity of a cluster of energy larger than $400$\tmspace  +\thinmuskip {.1667em}MeV, in the ZEUS calorimeters; bottom left: Similar observation in the H1 DIS $\eta _{max}$ distribution compared with a simulation which included diffractive and genuine DIS events. Right: An example for a recent measurement of the diffractive DIS cross section as a function of $Q^2$ for different $\beta $ at $x_{IP}=0.01$. The data are well described by a theoretical model based on QCD evolution of diffractive parton densities using a Regge factorisation ansatz. }}{8}}
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\@writefile{lof}{\contentsline {figure}{\numberline {7}{\ignorespaces Development of the integrated luminosity at HERA over time. Left: Status in September 1994 as presented by Ferdinand Willeke at an upgrade meeting; right: The luminosity delivered by HERA in the first phase (1992-2000) and the upgrade phase (2003-2007). The last four months were devoted to the lower proton beam energy runs. The trend resembled HERA I as the luminosity is proportional to $E_p^{-2}$, i.e. the factor 3-4 loss due to the reduction of $E_p$ at the end of HERA's operation brought the luminosity back to HERA I values of about $10^{-31}$\tmspace  +\thinmuskip {.1667em}cm$^{-2}$\tmspace  +\thinmuskip {.1667em}s$^{-1}$.}}{9}}
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\@writefile{lof}{\contentsline {figure}{\numberline {8}{\ignorespaces Left: Projected measurement of $R=F_L/(F_2-F_L)$ as presented to the upgrade meeting in September 1994. The plot indicates the need for an upgrade of the backward region for accessing the region below $Q^2$ of about $10$\tmspace  +\thinmuskip {.1667em}GeV$^2$. Right: Measurement of $F_L$ with data taken 15 years later. In the low $Q^2$ region the predictions from various fits differ most, and the H1PDF2009 calculation tends to be below the still preliminary data.}}{10}}
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\@writefile{lof}{\contentsline {figure}{\numberline {10}{\ignorespaces Parton distributions as determined by the QCD fit to the combined HERA I data at $Q^2 = 1.9$\nobreakspace  {}GeV$^2$ (top) and at $Q^2 = 10$\nobreakspace  {}GeV$^2$ (bottom). The inner error bands show the experimental uncertainty, the middle error bands include the theoretical model uncertainties of the fit assumptions, and the outer error band represents the total uncertainty including the parameterisation uncertainty. Here $xS = 2x(\overline  {U} + \overline  {D})$ denotes the total sea quark density. }}{12}}
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\@writefile{lof}{\contentsline {figure}{\numberline {11}{\ignorespaces Combined H1-ZEUS HERA I measurement of the reduced neutral current cross section $\sigma _r$, which at lower $Q^2$ and $y$ is a direct measure of the proton structure function $F_2$. On the right side the $e^-p$ and $e^+p$ cross sections are shown as open and closed symbols. The lines are from an NLO QCD fit to these data, from which at high $Q^2$ charge asymmetry effects are clearly visible which result from the charge dependent $\gamma Z$ interference cross section term. }}{13}}
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