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Site Details ATF Newsletters 
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2001 ATF NewslettersJan | Feb | March | April | May | June - July | Aug | Sept | Oct | Nov - Dec
Hi, April has been a relatively quiet month, however we still have a landmark result: The new ATF terawatt picosecond CO2 laser has delivered power to an experiment. The experiment is AE22, "Study of Compton Scattering of Picosecond Electron and CO2 Beams". The power has not reach yet the full terawatt level and commissioning is proceeding on schedule. A precise measurement of the power will take more time but Igor estimates somewhat over 0.1 TW. Ilan Ben-Zvi.
During the last several run weeks energy vs. distance measurements were done after the system was peaked up. A power gain length of 18.5cm was measured and a gain of 2*10^6. Also, through Section 4 the energy was observed to deviate from exponential, indicating the onset of saturation. The system was run ~70-90A and emittances 1-1.8mm-mrad were measured. Beam measurements were done after the system was peaked and will be continued in the future. More study is needed on the beam parameters. In addition to the energy results above, harmonics were measured. We have captured in a single shot spectrum not only the fundamental (840nm) but the 2nd (420nm ) and 3rd (280nm) harmonics. Initial energy measurements shows the 3rd harmonic to have ~1% of the fundamental. Our last run blocks concentrated on high gain measurements. Another energy vs. distance measurement was done, not at the peak performance reported last month, but a gain length of 20cm was measured at ~200pC. This is a little bigger gain length than last time (18.5cm), but confirms the system performance. By raising the gun phase, the charge was increased to 550pC. A gain (I/Io) of 5*10^4 was measured and the spectrum had much more structure due to the fact of its longer pulse length. Not much tuning was done to get this point, but we wanted to demonstrate reasonable lasing at higher charge. Currently, it looks as though our operating point will be around 200pC. See also: http://nslsweb.nsls.bnl.gov/nsls/esh/Highlights/Hilite%20Frame.htm Date: April 26, 2001 Lesson-learned from Recent NSLS Non-conformance Does this label look familiar to you and do you understand what it means? (Left side of label has a red circle with a red slash through it. Inside the label is a person with an outstretched hand indicating "STOP". Right side of the label reads: !WARNING DO NOT DISTURB! This device is part of the NSLS PERSONNEL PROTECTION SYSTEM. Any questions, phone x7527, x5770 or control room x2550.) We recently experienced a situation where personnel were inappropriately working within an electrical box identified with this label. The purpose of this ES&H Highlight is to ensure that all personnel at the NSLS who may encounter this label understand exactly what it means and what your obligation is. Interlock systems are a key element of the personnel protection at the NSLS. There are about 70 radiation protection interlock systems at the NSLS, including those at the SDL and ATF. The purpose of these systems is to ensure that no one is accidentally exposed to the radiation fields that are present within the accelerator enclosures or beam lines when the accelerator is operating. It is important to maintain the integrity of these interlock systems. Any work on components of these systems must be done either by the Interlock Group, or under the supervision of the Interlock Group. Entry to junction boxes or electronic chassis that are part of the interlock system by anyone other than a member of the Interlock Group is prohibited. These boxes are identified with the label shown above. If you find you need to get into such a box, you must contact the Interlock Group who will determine how to proceed. If you have any questions or comments, please contact Scott Buda (x3914) or Tom Dickinson (x7196)."
Last Modified: December 3, 2007 |
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