what difficulties would arise, and the second was to recalibrate the beam-current-monitor cavity. Prior to the first mA run, we ran 0.6 mA for several hours to check cathode lifetime, and it changed imperceptibly during that run. However, on the negative side, the cathode degraded substantially during owl shift this (Friday) morning, apparently in association with a brief surge in the gun current that occurred during pulsed-beam operation. Presently, our plan is to recesiate the cathode on Monday, 8 Jun 98, and check it then. Today we are able to get close to 60 pC bunch charge and are continuing injector setup.

Injector setup has been hampered by some technical difficulties. First, we continue to see substantial changes in what appears to be the rf phase of the drive laser, and the drifting makes it difficult to phase the accelerating cavities. We subsequently instrumented areas in the vicinity of the cabling associated with the drive-laser rf system for thermometry, but have not seen any inordinate temperature fluctuations. This finding, combined with checks done during our recent down time, means we still do not know what is causing the drift. Second, we set forth last night to calibrate the gradient of the buncher cavity that precedes the cryounit following a procedure that centers on bunch-length measurements with the first M_55 cavity, but we were stopped by a failure of the calibration routine for the M_55 cavity. The problem is being investigated today.

Our priority effort at this time is to calibrate the gradients of the cryounit cavities. Per the control screen, they are presently at their nominal settings, for which the output momentum should be 9.99 MeV/c. The injection-line dipole string is now set to 9.12 MeV/c momentum, about 8% low. This detail is a potentially important one insofar as it might influence calculated beam properties, i.e., PARMELA simulations. The effect on the simulation results is presently under study.

Progress on emittance measurements has been slow but steady. Measurements of emittance at the cryounit exit with Multislit #1 give a normalized emittance of about 5.5 mm-mrad. A preliminary analysis of data taken with the multimonitor and quad/viewer techniques indicate an emittance at the wiggler location of about 6-7 mm-mrad, less than the target value of 9 mm-mrad. These measurements were slowed by ghost-pulse saturation of key viewers. Last night it was found that the analyzer polarizer at the output of the second electro-optic cell had been photorefractively damaged. The polarizer was replaced, and the ghost-pulse problem appears to be solved. In addition, two of the cameras were falling in and out of beam sync, inhibiting the quad/viewer measurements, and these cameras will be diagnosed Monday.

Concerning other progress on "Subsidiary Tasks for Phase Space Metaprocedure", we have obtained agreement between the energy-fixed-point and transient-phasing methods for setting the rf phase of the buncher cavity.

Regarding the Happek device, in essence, it converts optical transition radiation from a foil into an interferogram that is a convolution of the electromagnetic fields impinging on the mirrors of the interferometer. A Fourier transform of the interferogram generates the electromagnetic spectrum, which in turn is proportional to the bunch form factor. Consequently, there is a direct relationship