Spectroscopy of Z>4 Quasars

We propose to measure the Xray spectra of 5 quasars with z>4. We have carriedout a survey of 14 optically bright, radioquiet z>4 quasars using short ChandraACISS exposures. From the measured fluxes, we can estimate exposure timesrequired for spectroscopy. To date, only four z>4 quasars have Xrayspectroscopy, and all 4 are radioloud blazars. Our sample includes one z5quasar, and we ask for a deep exposure which may detect its flux to 60 keV inthe rest frame. We can test whether the high energy turnover seen in localSeyferts is present in this z5 quasar. The only other z>5 quasar with ameasured Xray flux is too faint to obtain spectroscopy in a reasonable exposuretime. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]