IR FEL Monthly Report for October 1996

Navy IR Demo Contract WBS Elements

WBS 1 Project Management

October 1996 was the fourth full month of activities for the IR Demo project funded by the Navy. A total of $1,919k of costs have been obligated. With respect to the planned accrual of project cost by October ($1,901k), $1,294k of work was accrued which accounts for 16% of the project completed. The actual costs accrued through October totals $1,391k. This results in a negative schedule variance of $607k (an increase over September of $330k) and a negative cost variance of $97k ( an increase over September of $39k). The majority of the schedule variance (~$550k) is in the WBS 9.6 Optics account. This variance accrued largely due to a delay in planned purchase of optical components until after the Sept. 26 Resonator Design review as requested by the Navy. Recovery of this backlog of purchased materials has begun this month and will continue. The earned value performance in WBS 9.6 will not recover until next April with the completed delivery of these components. However, this effort is not on the critical path and presently shows one month of float. The only other WBS account with a significant schedule variance is WBS 7, Beam transport, which has a negative schedule variance of $163k. As noted in the WBS report, we are actively providing this WBS with additional labor to compensate for the schedule slip.

The $3.5M FEL Facility is still running over one month ahead of the established performance schedule; 1,302k of actual costs have been accrued and the facility is 45% complete.

The Omnibus FY97 Spending Bill was signed by President Clinton on Monday, 30 September. It includes $6M for continuation of the Navy's FEL Program. On Oct. 3, John Albertine and Fred Dylla gave a briefing to Eli Zimet of ONR on the status of the Navy FEL program and discussed possible outyear (97-98) activities with the FY97 funding increment.

Efforts continued to produce a detailed project schedule for completion and installation of key FEL subsystems. This activity is being paced by the continuing excellent progress with the facility construction that will currently allow preliminary installation activities to begin in January. Interim milestones for the IRFEL Program were finalized . They are serving as a communication aid in phasing the Accelerator Division resources that will be needed for installation, alignment, and checkout of the various subsystems.

Summary reports of the working groups that participated in the LPC Workshop on Sept. 9-10 and the MW FEL Workshop on Sept. 24-25 were received and edited for the respective proceedings. The proceedings were distributed to workshop participants. A subset of the Laser Processing Consortium met at the National Symposium of the American Vacuum Society in Philadelphia on Oct. 15 to continue plans for user collaboration and user facility proposals.

SURA held a review of the institutional management of Jefferson Lab on Oct. 28-29. An FEL program overview was presented at the review in addition to "customer" statements by John Albertine from the Navy FEL and Mike Kelley, chair of the LPC. A technical, cost and schedule progress review of the IR FEL Demo project was held on Oct. 29 by the Navy and DOE.

A draft agenda was circulated to the chairman of SURA's Maritime Technical Advisory Committee (MTAC) for the committee's first meeting on Dec. 17-18.

WBS 5.0 Instrumentation & Controls

Beam Instrumentation: The prototype 2 inch diameter BPM was completed. This is currently being tested, the initial results show a drop in the response at 1455MHz. This result is being evaluated, it may require a modification in the design. If a new prototype is required this would delay the delivery of the total 25 pieces till late in January, this is still prior to the fabrication of the griders. The BPM electronics modification design is proceeding, this is slated for a design review in November. A total of 28; 4-channel type electronics have been located from CEBAF machine surplus. The modification will be external attenuators and filters.

The shielded beam viewer contract was awarded and is on track for delivery in mid December. Some of these will be used in the 10 MeV Injector Test Stand (ITS). The control chassis that interfaces these units to the EPICS control system are in fabrication. The printed circuit boards have been procured and assembled; the chassis parts are being fabricated. The first unit is being used in the ITS.

The path & bunch length system was reviewed in October, it has been approved for construction with minimal changes. This will use a cavity nearly identical to the CEBAF system.

A second method for measurement of bunch length based on autocorrelation of the Optical Transition Radiation signal. The device is contracted from Uwe Happek at the University of Georgia, it uses a Michealson interferometer. The stepper motor on the device is controlled with the same system that drives the HARPs.

Personnel Safety System: Procurements are proceeding, roughly 80% of the required requisitions have been written. This system is a copy of the CEBAF system with the exception that the control is from the Main Control Center (MCC). A design review is scheduled for November.

Machine Protection System (MPS): The start of this system design was delayed by a month but things are proceeding well. The hazard analysis is nearly complete. This system will be based on the Argonne (APS) MPS system; this system has been in operation for three years and is fully operational in EPICS. We will procure the required printed circuit boards directly from the people at APS. The CAMAC based Beam Loss Monitor (BLM) boards will be converted to VME at CEBAF. This activity will start after the design review. The ITS will use one of the existing Fast Shut Down (FSD) and one of the BLM boards from CEBAF.

Control System Hardware: The review for the computer server & network configuration is scheduled for Thursday Nov. 21. Procurements for racks and IOCs were made in Oct. and will continue in Nov. This area is on track. A "loaner" server will be installed in the ITS in November to support the 10 MeV experiments this spring. This server will provide additional network isolation and support continued software development.

Control System Software: Progress continues to be made, much of the low level software driver work that is required for the new machine is (will) be used in the ITS. Of particular note is the multi-slit emittance monitor; J. Song has completed the code for the VideoMax digitizer. This new system is a real-time emittance monitor which will calculate the emittance at 4 Hz! There is a considerable amount of work just to construct the data bases for the new components. This effort was reviewed and priorities have been assigned to the task list. The software group feels they will be able to meet the schedule without impacting the work scheduled for the CEBAF machine.

DC Power: Trim rack fabrication has commenced. There is still a question on which trim cards will be made available from CEBAF. The decision is that we will not reproduce trim cards. The shut details are being worked out but the final numbers on magnet current & voltage drops has not yet been made.

Vacuum Controls: The vacuum design review was held Oct. 31. There were no major changes to the system. Ion pump power supplies are still be fabricated. 50 units are being assembled in parallel. The design and fabrication of the vacuum will take place in Nov. & Dec. There are enough CEBAF spares except for two of the PC boards. The layout are complete and they are being fabricated of site.

WBS 6 Cryogenic Distribution

The FEL/CHL BC is complete. It has been transported to CHL. One section of the tunnel return transfer line is complete. We now have 300 ft. of completed transfer line. Detail design of all supply transfer line modules for the FEL building are complete. Two have been released for fabrication. All materials are here or on order for all supply transfer line modules. Fabrication of the first all supply transfer line module is 95% complete and the second is 25%. Detail design of three of the five sections of FEL building return transfer line are complete, the other two are 99% and 75% complete. The CHL header extension fabrication is complete and installation is 90%. Detail design of all FEL CHL U-tubes is complete. Fabrication started on Nov. 1.

WBS 7 Beam Transport

Dipoles: field clamp tests on the prototype dipole yielded a K of 0.24 and a virtual total cut-of of fringe field. D. Douglas is confident he can build a better lattice (slight changes in dipole edge angles and magnet positions) with the new K value. The design change on all dipoles set back all plans to go out for bid using the drawing sets prepared to date. Design work started on transforming the drawings to the new saddle style with a field clamp using the Northrop Grumman designer. To reach our September 30 goal, the once liberal scheduled fabrication times have been reduced to times demanding just-in-time delivery.

The field clamped prototype dipole above will be used to test the uniformity at low field of the injection chicane dipole. The design concept involves the use of high mu material at the poles, separated by a small gap, to distribute the field to high precision over the entire volume at low field. The high mu material is on order.

Quadrupoles & Sextupoles: The weak quadrupole is in the hands of procurement on time while the trim quad is running late, still being made in the shop. The design of the prototype sextupole is at the sign off stage, on time.

Vacuum: The review of the vacuum system, including impedance analysis, vacuum hardware and vacuum control/interlock electronics was held on October 31. The review panel concluded that impedance issues are within budget for this machine. The system pumping and design concepts were judged sound and ordering standard parts, pumps, valves and bellows could proceed. Principal review panel recommendations were that both the method of interfacing the baked system to the non baked system and the methods and emphasis on the handling of particulates needs greater attention.

Installation: The first meetings with the principals involved with installation were held to begin planning their activities and assuring that the right hardware arrives at the right time.

General: With more manpower available from the Engineering Group, the pace of the Beam Transport System picked up considerably. Stands and girders for the injector as well as cable trays for the beam vault were laid out. The diagnostic system was frozen and a change review board appointed to police the freeze. Therefore, detailed design of the vacuum system begin in earnest. Reducing the cost from the increases in scope still remains an issue.

WBS 8 RF Systems

The Buncher System was conditioned to 25 % above full gradient. The system tests will be finished after a short punch list is completed. The control valve is sticking from time to time and a new one is on order.

Testing has started on the IRFEL cryomodule control racks which will run the 8 kW klystron HPA. Proposals have been received for the 225 kW variable DC power supply, but we may have to ask for re-bids due to an error involving small business set aside.

The documentation of the ITS Master Oscillator system was completed this month.

The remote controls for the Buncher system are installed and tested. The design and installation efforts for the remote controls for the quarter cryomodule unit are nearly complete. Testing the software with EPICS will start in November.

The fiber optic Arc Detector units are now installed and operational for the 50 kW klystrons and circulators.

New drive probes for the Chopper Cavity are installed. Preliminary tests indicate they will be able to operate at the 200 watt level without over heating. Additional tests will be run in early November.

WBS 9.2 Injector Move

A design review of the high voltage power supply was held October 25th. The design concept was accepted and it was decided to have an outside firm bid on the construction of a high voltage pressure vessel. It was also decided to use a gas mixture at moderate pressure as the best compromise between cost of the high voltage vessel and the consumables. We decided to pursue the purchase of a clean room for the photocathode drive laser instead of moving the existing room. This will speed up the schedule significantly and will leave the Injector Test Stand in much better shape to test out new injectors. Conceptual designs for the photocathode drive laser optical transport line have been developed. One of these will be chosen when the designs are reviewed in November. Work started on laying out the cable trays and crane systems in the injector area of the FEL facility to eliminate interferences.

WBS 9.4 Wiggler

All mechanical drawings were signed off at STI Optronics. The top level assembly was sent to Jefferson Lab and incorporated into the assembly drawing for the support girder. It was decided to use a commercial optical bench to support the wiggler, vacuum chamber, and nearby electron beam magnets and diagnostics. The bench was specified and will be purchased in November. A meeting was held with installation and alignment personnel at Jefferson Lab to go over the installation and alignment requirements and schedule. A conceptual design for the vacuum chamber and its support was developed. Northrop Grumman was selected to design these items.

WBS 9.6 -- Optics

Following a successful review last month of the optical cavity systems, procurements were made on "catalog" items such as mounts, and vacuum hardware. We are beginning to receive this equipment. Procurement of fabricated components was slowed by the need to define some vacuum specifications, but we will begin their procurement next month. We received all the major components (e.g., CO2 laser, chiller and CaF2 mirrors) for our mirror heating test stand. We are planning on beginning experiments before the end of November.

Operation of the ITS drive laser turned up problems with the electro-optic modulators, and with spatial jitter of the intensity distribution across the aperture. Short term solutions to the former were implemented. We have solutions (decrease the turbulent airflow across the optics) for the latter that will be implemented.





Injector, SRF, Facility, and Other Activities Outside Navy IR Demo Contract

Injector Test Stand (ITS)

All of the components on the experimental beamline were commissioned. Three operators from the nuclear-physics machine were trained on the setup of the present machine configuration. By the end of the month we were running two-shift operations and were on the verge of starting production runs to take publishable data. These developments were not devoid of technical difficulties, however, as is documented in detail in the weekly reports.

We decided that the new high-voltage (HV) stack will be of the same configuration as the present stack, but with two new, comparatively high-glass-phase ceramics. This plan, because it involves no engineering changes, results in the least schedule impact, and it permits a systematic methodology for understanding the cause and cure of the vacuum leaks produced in the present stack when it is subjected to >350 kV. Projected completion date for the new HV stack is 26 November 1996.

Fabrication of the cryounit was completed, as were almost all of its acceptance tests. The performance of the magnetostrictive tuner meets its frequency-range specification. Microphonics data indicate that microphonics are not a problem. Low-gradient unloaded Qs were measured and were favorable. On one of the cavities, the unloaded Q was measured to a cw gradient of 9 MV/m, at which point the rf power available in the Cryomodule Test Facility was exhausted. (We are in process of adding to the available power.) Plans are to finish all measurements of unloaded Q for both cavities during the week of 4 November 1996, at which time acceptance tests will be complete.

RF testing of the chopper cavity, which will be needed for measurements of bunch length as part of the reconfiguration of the ITS for 350 keV operation, was completed successfully. Fabrication and acceptance tests of the ITS beam-position monitor were successfully completed. RF conditioning and acceptance tests of the buncher cavity were successfully completed. All of the drawings for the 50 kW rf system were completed.

WBS 3 Cryomodule

Cryounit acceptance testing has been completed. Initial data reduction indicates all systems meet specification. Final data analysis will be completed in the next week. All significant redesigns resulting from the cryounit tests have been completed.

Orders are out for all bridging components with the exception of the cylinders. Quotes are due the 22 November for cylinder quotes. Budget of $6000 and 4 months for the cylinders is thought to be more than adequate. All other major procurements are in place.

Received the cavity pair beam line isolation valves and acceptance testing is underway. Cavity final qualification continues with 25% complete and 25% expected in November.

WBS 2 Beam Physics

Impedance analyses for almost all components of the IR FEL were completed, the principal exception being that of the newly specified beam scraper which recently entered into engineering design. We are well below the accelerator's impedance budget. This information was fed into an internal vacuum-system design review held on 31 Oct. 96.

An analysis of the rf hardware and control system was completed. The basic conclusion is that the CEBAF rf system can be adapted for use with the IR FEL without any near-term revision of the control software.

The suite of electron-beam diagnostics for the IR FEL was frozen. Principals for all of the electron-beam diagnostic tasks were identified and lined up. Tasks involving significant development effort are already well underway. Tasks not yet started involve, for the most part, adaptation of hardware and techniques already implemented on the nuclear-physics machine. A list of diagnostics tasks now appears on the WWW. In connection with freezing the diagnostics, a "change-order process" was defined involving a Diagnostic Review Committee to consider change requests. It has already met once to consider nominal changes to the baseline diagnostics suite that were proposed as a result of further considerations of commissioning procedures, such as that of the injection line.

A preliminary thermal analysis was done for the straight-ahead dump that will be used in generating first light. Also, detailed requirements were identified for the beamline leading into this dump. This beamline was subsequently designed, and the necessary beam-rastering magnets were specified. A similar design was also completed for the beamline leading into the injector dump, again in order to specify the necessary beam-rastering magnets. A similar analysis is underway for the beamline leading to the energy-recovery dump.

A simulation of the IR FEL injector with first-light beam was run. It indicates that we can compress 33 pC bunches down to rms bunch lengths of about 0.5 ps by the time they reach the entrance to the linac, a favorable result.

Exploratory linear-transport analyses was done throughout the month to assimilate the fringe-field data taken for the prototype dipole magnet. In every case, these fringe fields were determined to have only a slight impact on the design of the beam-transport lattice. The effort to optimize both the lattice and the design of the dipoles continues.

WBS 4 Commissioning/Operations

The required alignment tolerances for the IR FEL were found to be softer than those of the nuclear-physics machine. Probably only one alignment pass will be needed during installation rather than the two that were projected, and so there should be a corresponding cost savings.

Timing modes were delineated to establish beam profiles for IR FEL startup, first light, and energy recovery, as well as for assorted ITS experiments. A preliminary list of gating and triggering formats was also compiled.

A layout of all of the trim magnets and their power supplies was generated as a precursor for preparation of the respective procurement packages.

A methodology for calibrating the beam position monitors (BPMs) was identified. It might be possible to adapt the quad-centering algorithm in the nuclear-physics machine to the IR FEL to speed initial BPM calibrations.

Considerable progress was made in delineating the control interfaces that are implicit in the design of the IR FEL. This has enabled us to get better organized with respect to identifying the required control software and generating the software that isn't already available.

Preparation of a Users' Manual designed to define user interactions, facility capability, and instrument availability was begun. This will be a living document that will be continuously updated to include new capabilities and new requirements from the users as they occur.

Facility

Facility progress continues on or ahead of schedule. The wall pours were completed for the lower level. Two thirds of the three foot thick concrete ceiling slab was poured nearly enclosing the lower level of the accelerator enclosure. It was discovered that the placement of the waveguide penetrations in one zone was off by 9 feet. The contractor intends to fill in those holes and add new penetrations by cutting the first 6" to clear the rebar and then jackhammering a large enough hole that a new properly positioned and sized hole can be cast in the 3-foot slab. A major pour of wall areas and shielding around the entrance labyrinth was completed. Initial work was done on the truck ramp access.

Specifications for the new clean room to be installed in the FEL Facility were revised. Although we expect that the new room will cost somewhat more than moving the old one, we believe that it would improve the schedule for moving the injector laser by about 2 months.

We laid out possibilities the optical-transport line for the FEL Facility and resolved issues concerning interference with cable trays and the clean hood for the gun.

Draft sketches for the Ethernet installation (done by Jefferson Lab personnel) have been produced are in engineering design. The phone systems have been ordered and most components received.

An initial draft of a user manual for the upstairs lab was produced.

Upcoming Meetings and Reviews

Internal Review of IRFEL Driver Nov. 15, 1996

Internal Review of Magnet Design Nov. 18, 1996

Maritime Technical Advisory Committee Meeting Dec. 17-18, 1996

Laser Processing Consortium Workshop Jan. 21-22, 1997

SPIE High Power Light Source Conference Feb. 8-14, 1997

DOE Basic Energy Science Review Feb. 24-25, 1997