Navy IR Demo Contract WBS Elements:

WBS 1 Project Management

A contract has been established with Los Alamos (J. Goldstein) to perform modeling of the FEL gain with mirror distortions. Signoff on the LANL end should occur shortly. The task is estimated to be complete in three months.

WBS 5.0 Instrumentation & Controls

The 2 inch round Beam Position Monitor mechanical design is complete. The drawings for the 2 inch version are complete and signed off. These will be prototyped next. There are 22 of these BPM's and 5 wide chamber BPM's. The design for these wide chamber devices will begin late this month. The 1 1/2 inch diameter shielded beam viewer parts are nearly complete (machining). This is a 'one of'.

The hazard assessment for the Personnel Safety System is proceeding. The long lead items are being procured for assembly of sub-systems beginning in Sept.

The machine protection hardware from Argonne lab has arrived and will be incorporated into the Injector Test Stand (ITS) for evaluation.

The software required for the IRFEL is being written for use in the Injector Test Stand (ITS). When the ITS is operational > 75% of the required software will be in use.

The electron beam macropulse controller is being integrated with the optical equipment. This device provides remote control over the drive laser shutters. The prototype functions now with a manual remote control. The device is currently being fitted with an interface to the Machine Protection System. Once this is complete the VME interface will be built.

The shunt requirements for DC Power have been identified. These are for the most part copies from CEBAF, procurements will begin in Aug.

The vacuum control are also progressing. Ion pump power supplies are begin procured as well as gate valve control cards. This system design is based on CEBAF existing systems.

WBS 6.0 Cryogenics

Pipe procurement is 70% complete. All pipe was due July 12. Final pipes to be shipped from mill on 8/9/96. FEL/CHL TL Bayonet Can for CHL fabrication was started on July 1, 1996.

Fabrication continues. Fabrication of FEL TL anchor at CHL started 7/11/96. Currently at 50%

complete. All materials to finish are on site. Detail design of FEL Building Supply and Return transfer lines is 33% complete. Piers for quad TL have been surveyed and vendor has been chosen. Total of PR's for July were $32,000. Fabrication crew size is now 4.5 people. Candidates for another position have been interviewed. One more person will be onboard by 8/9/96. The stands for fabrication of the Quad TL are 95% complete and will be finished by 8/6

WBS 7.0 Transport

The number and style of magnets was settled on.

The Optical Chicane Dipole Package was virtually completed by V. Christina of Northrop Grumman.

The first test of the prototype main quadrupole took place, verifying field calculations and coil fabrication quality. Further tests are necessary to compare the magnet to the standard QB. There is a two week conflict in the use of the Test Stand because Operations at the CEBA are asking for a population study of 6 QAs to verify the field zeroing procedure recently worked out on one magnet.

Prototype design of the Injector Dipole Prototype has been put off and may not be necessary because the research will take place on the prototype reverse bend dipole due in early August.

The request for bids for the copper for major dipoles is out to vendors.

Work on the Trim Quadrupole has not started because of the lack of engineering manpower.

The configuration and the general specifications for the Vacuum System were fixed.

Outstanding major issues remain: (1) increasing the engineering and design personnel available (2) generating accelerator physics lattices for the dumps and (3) reducing the cost from the increases in scope.

WBS 8.0 RF Systems

The low head pressure water systems have been installed on both klystron carts and are fully operational.

A change to the Cathode Power Supply (CPS) is being considered to enable operation of the IR FEL linac klystrons at 8 KW. A modified specification and cost will be reviewed in August.

The Buncher Cavity is complete. It is vacuum tight, on the correct frequency, and is properly RF matched. It will be full power tested as soon as the water skid and waveguide are connected.

The HOM filters were tested at low power and the data looks like the factory test data. The first unit was tested with 30 kW of high power RF and the temperature rise was about as expected.

The prototype Arc Detector system was finished, tested and installed. It will be used until the finished units are produced.

The Chopper Cavity and its water skid were tested to 200 watts. The new input probe was overheating at this level and water cooling will be added.

The first waveguide elbow with the rupture disk and window for the arc detector has been installed and tested on the first klystron. It meets all specifications.

WBS 9.2 Injector Move

The HV engineer has determined that Glassman cannot provide much help on the high voltage power supply modifications and is therefore working the problem himself.

We are trying to get a reasonable price for moving the drive laser clean room enclosure.

WBS 9.4 Wiggler

The contract for the IR Demo wiggler was awarded to STI Optronics on July 1. The magnet design review was held at STI Optronics on July 29 and attended by S. Benson and L. Harwood of Jefferson Lab and S. Gottschalk of STI. A summary of the review is being prepared and should be released on Aug. 5. The design is almost the same as an existing device which meets almost all the technical specifications.

Obtained price estimate of approximately $7k for an optical bench to be used for supporting the wiggler and magnets near the wiggler. This support is sufficiently stiff to allow the magnetic structures near the wiggler to be treated as a single rigid unit. The mounts of the wiggler and magnets to the bench should be quite simple and inexpensive to design and build.

WBS 9.6- Optical Systems

This month progress was made in several areas. A long path length (~ 22m) Mach-Zehnder interferometer was successfully tested, and work on it now turns to instrument and computer interface it. Our tests of the applicability of an in-house spectrometer and PDA to rapidly acquire spontaneous emission spectra are progressing. Finite-element analyses on the temperature distribution in various optics progresses and next month we will use them to refine our input to our physical optics code. Procurement of optical components is progressing.

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

Injector

Development of vacuum leaks in the ceramics comprising the high-voltage stack inhibited progress in the photocathode-gun program. The cause of the leaks traces ultimately to field emission from the concentric metallic stem. In response, we have taken two important steps. First, we have identified three corrective measures that can be implemented in follow-on stacks, and we are pursuing all of them. These include: (1) procuring new ceramics with high glass-phase content which, based on previous operational experience, ought to have sufficient conductivity to preclude arcing at 400+ keV, and this would enable routine operation of the gun at 350 keV, a sufficient voltage for the IRFEL; (2) installing a cylindrical sheet of insulator, such as mica, between the metallic stem and the ceramic; (3) coating the metallic stem with a field-emission-suppressing material. Second, we are restructuring the schedule to shorten the time for experiments to measure the phase-space properties of the gun's output beam. Specifically, we are presently looking at a redesign of the beamline that would enable conducting the transverse and longitudinal phase-space diagnostics in parallel. In the meantime, plans are to operate the gun at 250 kV to generate high-current beam and correlate measurements of beam properties with simulations. Replacement of the existing stack with a new one will occur in the November time frame.

Selection of the cavity pair for the ITS cryounit took place. The cavities meet specifications for both accelerating gradient and rf power dissipation. Construction of the cryounit is in progress.

SRF (WBS-3)

Cryomodule bridging bid package completed. Procurement is on track for a

scheduled December.

Three inch rf shielded bellows design ready for sign off.

Three inch cavity isolation valve qualification testing underway. Base

line measurements complete, expected full completion 8/15/96.

Prototype helium vessel/HOM load assembly 50 % complete. Expected completion

8/12/96.

Focus continues on completion of stainless steel beam line components, HOM

load assembly, and cryostat final designs.

ITS 1/4 Cryomodule

Activity Expected Completion

Cavity Pair Complete

Cryounit 8/16/96

1/4 Cryomodule 9/6/96

Acceptance Testing 9/28/96

Installation 10/2/96

Beam Physics (WBS-2)

The magnet count was finalized for the entire IRFEL transport system, to include the injection line, recirculation loop, and all dump lines. Detailed designs of the transport lines for the IRFEL's injector dump and recirculation dump were started. Moreover, we took a cursory look at the requirements for the beam-transport system of the 1-micron IRFEL and found no serious impediments to its development.

Burn-through analyses indicate that the tune-up beam can run in 250 microsecond pulses, which is long enough to circumvent rf transients and also to permit use of the 4-channel BPMs.

Calculation of impedances of beamline components is proceeding systematically and routinely as component drawings become available.

Established the vacuum specifications for the beamline of the IRFEL. This involved assuring that ion trapping would not significantly degrade the electron-beam quality. Although refined calculations of ion trapping are forthcoming, initial calculations establish with confidence the viability of the vacuum specifications that had initially been projected.

The design of the 10 MeV transverse-emittance measurement apparatus was chosen based on a similar instrument made at UCLA. Work on its development continues.

We began exploring the physics of coherent synchrotron radiation from the perspective of particle-particle interactions in preparation ultimately of building a particle-simulation code to include the effect.

Commissioning (WBS-4)

The FEL commissioning workshop was held on July 24 and 25th at the Thomas Jefferson National Accelerator Facility with a loose agenda focused on producing first light as easily and quickly as possible. In attendance were Pat O'Shea of Duke, Alex Lumpkin of APS, and Ira Lehrman of Northrop Grumman. Boosting the gain was stressed as a means to first light. Increasing the beam current, decreasing the gap of the wiggler, and increasing the first-light wavelength were all strong suggestions that came out of the Workshop.

The Injector Test Stand experimental schedule was published this month on the WWW. It projects completion of the 10 MeV test in June 1997. Burnthrough calculations for the machine were completed and fixed the "Setup" mode for the machine. This mode and a tentative commissioning plan was passed to the Machine Protection System designers to start that design.

Facility

The conventional construction continues on schedule. Progress payments exceeding $ 500k have been made to the contractor. No significant safety violations have been noted. The digging of the lower level is nearly complete. Forms were set for the first part, rebar laid in, and the west end of the bottom floor cast despite heavy rains during the last of the month into early August. Progress is being made in tying in the site power and water with the actual connection to the site systems scheduled in early September to coincide with an accelerator shutdown.

Upcoming Meetings and Reviews

International FEL Conference and August 26-30 at Rome

Applications Workshop

High Power Development Planning September 24 at Jefferson Lab

Optical Cavity Design Review TBD end September