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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
The summer days are slow on account of conferences, vacations and maintenance shutdowns, so this communication will be brief. After many years of on and off work at the ATF, Bob Harrington has resigned. We wish him success in his new endeavors. The 21st ICFA Beam Dynamics Workshop on Laser-Beam Interactions was held during June 11-15, 2001 at Stony Brook and Brookhaven. The Workshop was chaired by I. Ben-Zvi and T. Hirose, the Program Chair was I. Pogorelsky and the Local Organizing Committee was chaired by M. Babzien. The workshop was immensely successful, with over 100 participants and a very rich scientific program. Ilan Ben-Zvi. The ATF went into shutdown following a highly successful period of operations. The purpose of the shutdown was to carry out urgent facility improvements, install new experiments, and provide ATF staff not involved in the shutdown a time for vacation. The major projects for the shutdown and their status is as follows: 1. Linac water system: the new linac water system was installed and successfully tested. This will significantly improve the ATF linac system stability. 2. New control system testing: A milestone was passed for the ATF new control system, as reported by Bob Malone below. 3. A new vacuum pump was installed to provide better vacuum isolation between the experiments and the ATF linac. 4. The 2 meter long HGHG radiator wiggler was removed without disturbing the VISA experiment, clearing space to install new experiments at the ATF beam line 2. 5. Surface wake field feasibility test has been installed. 6. The Minos experimental setup has been removed after the successful run, to allow the CPOD experiment to run. 7. There are delays in the work on modulator protection circuits, micro-bunch detector, vacuum acceleration, new dipole magnets in beam line 1, and chiller maintenance due to various reasons, mostly shortage of personnel.
Since the beginning of June, there have been two major accomplishments in the ATF computer control system upgrade, Successful porting of user display windows and concurrent hardware sharing. 1) Successful porting of user display windows All of the operator displays in the ATF control system have been ported from VMS to Linux. The entire set of 894 graphic user displays were updated using a two step procedure: i) The old VAX graphics files were sent electronically to Vista Control Systems who processed them using software tools they had developed for in-house use. The resulting displays were returned to BNL for further processing. (Special thanks to Peter Clout and Virginia Martz, both of Vista Controls, for their outstanding assistance in this effort.) ii) The displays as received from Vista still had embedded VMS file and directory syntax, along with other artifacts of VMS-all of which had to be replaced with proper Linux syntax. Each of the 800+ displays was analyzed (using an elaborate PERL script written at BNL), the VMS-specific entries were located, removed and replaced with appropriate Linux equivalents. From an ATF user/operator perspective, this is an important achievement: It means the new upgraded control system will appear visually identical to the old one; no operator re-training will be required. 2) Concurrent hardware sharing The new Linux control system host and our present VAX host are now sharing the CAMAC data acquisition hardware in all of our crates. The VAX continues to communicate with the CAMAC via the L2 serial crate controllers and operates as the CAMAC bus master while the Linux machine uses Ethernet crate controllers, configured as auxiliary (slave) controllers. Under this master/slave arrangement, the two machines share the CAMAC bus in each crate with the VAX having the higher priority and the ability to lock out the Linux machine during critical CAMAC cycles. This is an especially important milestone since new Linux software can now be tested against the full ATF hardware load. Such testing can take place on weekends, maintenance periods or any other time when the main control system is not needed to support users. The switchover time between systems is about 15 min. and requires no recabling or other hardware manipulation since the change is made entirely in software. This arrangement also the advantage that any anomalous behavior in the new Linux system can be understood more quickly by direct comparison with an already proven system.
Last Modified: December 3, 2007 |
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