Feb-March 2002: To get a short CO2 pulse, we plan to use the YAG laser and a Kerr switch to slice the long CO2 pulse, and a pulse length shorter than 5 ps is required.

October 2001: During the last shutdown period (10/22-10/27), significant effort was made in understanding the limitations encountered when using so called "Gaussian" or graded reflectivity mirrors (GRM), for transverse profile shaping in the system.

January 21, 2000: Pulse shortening by saturable absorber: Testing of the saturable absorber shows good results so far.

February 18, 2000: This week the testing of the new laser oscillator confirmed last weeks results that showed unacceptable phase, pointing, and power stability from the unit.

March 24, 2000: Last week after the failure of the Pockels cell driver, it was decided we could use the time while the driver was under repair to start some laser work needed to improve stability.

March 31, 2000: This week the laser operated five days for experiments, with only a couple of hours required on Thursday for CW realignment to restore good amplitude stability.

April 14, 2000: Monday urgent realignment of the demo oscillator was performed to restore optimum mode locking, phase stability, and output power.

April 21, 2000: The maintenance this Monday involved several miscellaneous tasks that had been accumulating for several weeks...

November 20, 2000: Work on the YAG system over the past few weeks has been primarily to improve amplitude stability on the cathode.

March 12, 1999: Operated >12 hours 3/6 + 3/7 for STELLA runs without realignment

March 19, 1999: 3/12: A quick study of laser beam exiting the gun was performed by collecting the light at the exit port and directing it to the streak camera in the gun hutch.

March 26, 1999: Over the previous weekend the YAG oscillator shut down on internal interlock.

April 16, 1999: A system of 11 thermocouple was installed to monitor the temperature in a few locations in the Yag room.

May 14, 1999: Last weekend work continued on beam studies and cathode cleaning was performed Friday. Sunday the laser was operated for pulse duration measurements.

May 21, 1999: Some time was devoted to understanding and improving amplitude jitter of the system.

June 4, 1999: The new YAG oscillator is back after exhibition at CLEO 99.

June 11, 1999: Good laser stability this week allowed reliable and productive delivery of beam to the gun.

July 9, 1999: During the shutdown to install the new oscillator, the oscillator enclosure has been expanded to allow kinematic exchange of the new and old oscillators with minimal disruption to the optics.

July 16, 1999: There is little to report this week because of very successful experimental runs. The laser reliability was very good for both the STELLA and HGHG runs.

July 23, 1999: Two days this week were devoted to laser work. Monday the alignment of the UV beam to the cathode was checked.

August 6, 1999: Tuesday and Wednesday were devoted to maintenance. The Pockels cell installed last week with the new high voltage pulser for double pulse operation was optically damaged.

August 13, 1999: The laser provided beam all week without maintenance and only minor realignment to the cathode, and oscillator power was stable within 2%.

October 22, 1999: The RF master oscillator supply was relocated to a new rack in the laser lab where the heat loading should not affect the YAG laser.

October 29 1999: There was laser maintenance on Monday during which the amplitude instability from ground motion was further studied.

November 5, 1999: This Monday’s scheduled laser maintenance was realigned of the oscillator, again because of degradation of the saturable absorber.

November 12, 1999: The maintenance day on Monday was used to set up some tests of the saturable absorber which could potentially be used to shorten the IR pulse duration.

December 10, 1999: Monday maintenance consisted of some mechanical work on interlock shutters, and, prompted by the BPM experiment results, another measurement to search for multiple pulses at the gun.

February 23, 2005: Since the last status report of the ATF CO2 laser in the ATF Newsletter of February 2004, much progress has been made toward bringing the CO2 laser in line with the increasingly challenging demands of ATF user experiments on advanced laser acceleration (STELLA LWFA, LACARA) and radiation sources (Thomson scattering, EUV).

February 2004: Our CO2 laser, being synchronized to the ATF linac, enables laser/e-beam interaction experiments. A number of such user’s experiments have been successfully completed over the past years.

Jan.-March 2003: The upgrade of the ATF CO2 laser system to a few-picosecond pulse at Terawatt peak power is a the final stage.

April-June 2002: In order to achieve terawatt peak powers with the ATF CO2 laser, it is necessary to reduce the pulse duration to a few picoseconds before seeding the amplifiers.

Oct.-Dec.2002: The testing of the CO2 short pulse upgrade is now beginning. Optics for delivering the YAG pulses to the CO2 room are in place, and have been aligned using a green HeNe laser.

September 2001: The ATF continues with the upgrade of the facility, in particular its high-power CO2 laser, in order to better serve the more demanding users' experiments.

February 4, 2000: In the continuing work towards the operation of the terawatt laser, the gigawatt pulse generated by the ATF CO2 laser was trimmed from FWHM 200 ps to 25-30 ps using a combination of a plasma shutter and a saturable absorber.

December 28, 2000: The ATF terawatt CO2 laser is not in service yet. However, a festive moment expected by the ATF users is approaching.

March 12, 1999: The acceptance test of the Terawatt CO2 laser amplifier built by OPTOEL Co. (Russia) has been completed this week.

May 21, 1999: Two-stage semiconductor optical system is reestablished and tested.

May 28, 1999: Optics installed to deliver the alignment and amplified CO2 laser beams to the auto-correlator to measure the duration of the amplified pulse.

June 4, 1999: Installation of beam enclosures for the CO2 laser transport line between rooms C1 and C2 and work on eliminating gas leaks in the CO2 laser preamplifier and in the terawatt amplifier are still in progress.