February: Chicane centerpiece diagnostic was installed and tested. Beam image was obtained in the middle of chicane.

January-March: VISA II will perform an experimental study of the physics of a chirped beam, SASE FEL using the upgraded facilities at the ATF.

April-May: In this period VISA achieved the first sustainable lasing after the renewal of the effort. Here is the summary of the results.

October-December: After compression, linear transport through final bending systems has also been found (notably in the first round of VISA experiments), to have dramatic effects on the final beam phase space, and thus the SASE process.

January 2001 : The last few weeks have been dedicated to moving the undulator (while in vacuum) to the correct position and a continuation of running the VISA system.

February 2001: We’ve had 5 run days this last block. Heinz-Dieter arrived last Wednesday and stayed through our runs this week.

March 2001: On behalf of the VISA collaboration, we are very pleased to announce that VISA has recently demonstrated a gain of 2x10^6, and an exponential growth rate (intensity gain length) of 18.5 cm.

April 2001:During the last several run weeks energy vs. distance measurements were done after the system was peaked up.

May 2001: Last week was the VISA meeting here at BNL. The talks went well.

August 2001: The VISA collaboration finished its last experiment run in the first week of June.

January 14, 2000 : On Tuesday, we propagated beam to Pop-in 1 which is just a silicon mirror without use of the BPM optic design.

January 21, 2000: A Molectron detector was set up at the FEL mirror of Pop-in 8.

January 28, 2000: We are currently preparing for the last run days before the shutdown.

February 4, 2000: We saw good OTR signal through the BPM using the more sensitive COHU camera.

February 25, 2000: Robert and his team came out and did an alignment using the laser interferometer this last holiday weekend.

March 10, 2000: We slowly pumped down the system and the vacuum looks good.

March 24, 2000: We were able to transport 100% of the beam (700pC) @ 71MeV with no corrector steering.

April 14, 2000: Last Friday’s run We did radiation vs. charge and it is still linear.

April 21, 2000: For our next two run days, we are going to solely study the trajectory and how to improve it by correction algorithms using the two upstream steering magnets.

May 5, 2000: XJ started at 9 am with laser profile and e-beam profile studies in the tunnel because there was observed structure in the e-beam profile.

May 19, 2000: These last two weeks were shutdown for VISA.

June 9, 2000: For PAST couple of months, Alex has been working on the upgrade of BPM optics, and alignment laser systems. Last run was a “beta”-test for both.

July 26, 2000: Data taken from the last runs indicate little correlation to the proposed correct trajectories sent out by Robert.

November 20, 2000: The big VISA shutdown has been completed and we are working our way towards a run.

December 28, 2000: After the shutdown was completed, we started running the VISA system again. Similar to last time, trajectory studies in the horizontal and vertical were measured.

March 12, 1999: Undulator Sections #2 and #3 were individually set up on the pulsed wire bench in the normal (upright) orientation for tuning.

March 19, 1999: Magnetic shimming of Undulator Section #4 was completed.

April 16, 1999: Undulator Sections #2 and #3 were checked on the pulsed wire bench.

May 14, 1999: The leveling of the undulator support stands has been machined and the redheads for the stands have been installed in the experimental hall.

May 21, 1999: There was a delay with the machining of the jig support plates and the pre-assembly for VISA will begin the week of May 31 in Building 726.

May 28, 1999: Ben Poling and Roger Carr will arrive at BNL next Tuesday evening, and work next Wednesday, Thursday, and Friday to re-assemble VISA, with the newly machined pedestals and table tops.

June 4, 1999: Three crates of Robert Ruland’s alignment materials have arrived. Holes in the top plates for the alignment fixtures that were misdrilled will be corrected.

July 23, 1999: George is continuing with the final undulator characterization and hopes to be done by next week.

July 30, 1999: On Monday, one more set of interferometry measurements was done on Sections #1 and #2 in the 90 and 270 degree orientations.

August 6, 1999: We need a new chiller for the 30 A power supplies required for VISA. Due to the fact that the ATF ran out of funding for FY99, a serious delay is expected in full energy VISA operations.

August 13, 1999: The undulator will be shipped back to SLAC to have the tooling balls fixed. Approximate delivery time is August 23rd.

August 20, 1999: The second alignment diode laser has been ordered. It operates at 660 nm, output power 10 mW.

August 27, 1999: The status of the undulator segments is that they are at SLAC, the tooling balls have been purchased and have had holes put into them.

September 3, 1999: August 30 Complete CMM measurements of undulator sections at SLAC and ship to BNL.

September 10, 1999: The undulator tooling fixtures took a little longer than originally expected.

September 17, 1999: The test beamline (ATF beamline #3) was run this week.

October 1, 1999: Last Monday, Alex and Vitaly conducted an experiment to test a YAG-crystal applicability as a VISA beam profile monitor.

October 8, 1999: Vacuum testing on the vacuum chamber is in progress. A low temperature bake was done and a small leak was found in one of the o-rings and fixed.

October 22, 1999: The apparently huge (up to 1.2 mm) closure errors between fiducialization and CMM data were due to an error in a spreadsheet reference.

October 29, 1999: Mirrors (for the diagnostic pop-ins) received from Opticraft ended up being no good... not even for the electron beam diagnostic.

November 5, 1999: A valve can be installed before the VISA undulator which will isolate VISA from the rest of the experimental hall beamlines.

November 12, 1999: The BPM was installed last Wednesday, and vacuum at VISA beam line this morning is 7x10^(-8).

November 19, 1999: Ben arrived and the vacuum chamber has been installed in the ATF and rough surveyed into place.

December 3, 1999: This week Robert and the alignment team are here and setting up the laser interferometer.

December 10, 1999: Robert and his team finished the alignment Tuesday morning. It was estimated that the alignment was peak to peak 100um over the 4m.

December 17, 1999: This week we finalized the chamber and upstream beamline and bolted up.