Activity of FNPL for week 12/13 to 12/17 Friday Dec 17 th, 2004 minutes at: http://nicadd.niu.edu/fnpl/Operation/Minutes/ * Plan for next week: - Monday, photoemission studies [Ray] - Tuesday, Wednesday, Thursday: flat beam studies [Yin-e, Philippe] * Last week activity - Monday, Daniel continued CTR measurement using the Golay cell. Although the signal is better than prior to the 300 kHZ amplifier installation, the autocorrelation signal is still noisy. Off line analysis (spectum calculation) will give a quantitive answer on the benefit of the Golay cell compared to the pyroelectric detector. At least the autocorrelation does not have any more deep gap on each side of the peak. - Tuesday, tested [Tim Koeth] the phase monitor (coming from DESY). The phase monitor output was sent to a 1 GHz scope and within the resolution we see the same signal as observed at TTF2 (Manfredt Wendt sent us a scope printout of the signal observed at TTF-2 DESY) - Wednesday, Thursday and Friday: Tunnel work [Wade, Rocky, Mike], the bunch compressor was removed and replaced by a new YaG screen located 80 cm downstream of X7 (optimized for emittance measurement of a flat beam) The multislit at X7 were replaced by two single slits. The slit width was chosen to be 3 mm based on calculation done with EGS4. The vertical slit (horizontal emittance measurement) was mounted on the horizontal stepping motor to allow to be scanned in the beam and the horizontal slit on the vertical stepping motor. In parallel the laser transport line was modified and a lens f=20 m was installed in the second mirror box. The lens was chosen to provide an almost one-to-one imaging of an object plane, located prior to the UV shutter, onto the photocathode. Test of this imaging with UV were suces- sful. We still need to locate a remotely controlable iris at the object plane location. ACTION ITEM updated: Sat Dec 11 08:17:39 CST 2004 H8/ calibration of upstream directional coupler and insulator (Markus need to speak to Tim and with Kai to schedule this STATUS?) H13/ Pulse stacker, what do we do? (Rodion) H21/ the laser uniformity problem can this be due to the new (since late summer) tight focusing in the doubling crystal area to improve conversion efficiency? On going work [Rodion] H28/ Problem with emittance measurement at X7 (Philippe 04/16/04) [DONE] H32/ Digital camera from SONY(?): [Philippe/Yin-e] to be TESTED with OTR [Sep 27] [FIXED, we have prototype] H33/ laser fluctuation since June 1st week [FIXED?] H34/ Need more work on power supply + devise a way to measure the current being put out to the magnet [Jamie] H36/ laser room/table vibration studies H37/ imaging system for the laser transport [Jianliang/Rodion] DONE H38/ controllable iris [Jamie] #.37 from Adrian Melissinos: NEEDED LASER STUDIES: 1. Study of oscillator bandwidth versus length of compressed pulse. Measure IR length using stepping autocorrelator [Done week of AUG 23rfd 2004] 2. beam profile (wavefront) studies both in IR and UV in laser room and on virtual cathode. Use spatial filters 3. study of doubling and quadrupling efficencies with old and new crystal, take a tuning curve POSSIBLE LASER UPGRADE PROJECTS 1. Measure IR pulse length before compression (use diode?) implement cw autocorrelation 2. Install new beamline between multipass and 2-pass -- install spatial filter, rebalance 2-pass amplifiers 3. Relay imaging UV from laser room to cave 4. _harware_: replacing all coolers with new system IV + use existing system III as back-up 5. pulse stacker studies, new pulse stacker R&D