FEL Upgrade Project Weekly Brief

March 11-15, 2002




We were pleased to host a very important set of visitors to the FEL Facility today; the Chief of Naval Research, Admiral Jay Cohen; Congressman Duncan Hunter, who heads the R&D subcommittee from the House Armed Services Committee and two local members of the House Armed Services Committee, Congresswoman Jo Ann Davis and Congressman Randy Forbes. We had the opportunity to give the delegation a briefing on the FEL program and a show and tell on the JTO-funded laser material studies and the CWM-NASA project on carbon nanotube production. By all accounts the visit was well received and we were honored to have the opportunity.

Support stands for the return leg magnets were installed in the FEL vault this week.

This is the first of the Upgrade hardware to be installed.


Needless to say the attention of project management this week was consumed by preparations for today’s important visitors. In addition, we worked on preparing documentation for the Virginia Research and Technology Committee for next week’s annual report to the Virginia Congressional delegation.

The project monthly report for February were prepared and readied for distribution next week.

WBS 4 (Injector):

While implanting the cathode support tube some arcing has occurred. We have decided to redesign the mount for the support tube in the implanter, polish out the damage and start again. The shop completed the gun mounting ring which mounts the gun chamber to the stand. Polishing was started on the ball cathode. A mount for implanting the ball cathode was submitted to the shop. The running portion of the resistor was received.

The three emitters found on the GaAs wafer used for testing field emission levels were identified as non intrinsic and resulted most likely from the handling procedure. Traces of indium where found on two of the emitters. Calculations show that for similar emitters on an activated wafer, the field emission current in the 6 MV/m configuration is on the order of pico-Amps, but at 10 MV/m the current is on the order of micro-Amps.

WBS 5 (SRF):

Received the thermal shield and receipt inspection has started.

WBS 8 (Instrumentation):

Magnet locations have been nailed down and cable installation plan is in order and will begin soon.

A test stand for beamviewers and cameras has been assembled this will test the operation of the solenoid and air valves as well as the sensors that indicate viewer position. We will also be looking at the indicators on the foil that will allow better determination of beam location and size on the viewer. Inputs into EPICS will also be tested.

WBS 9 (Transport):


Optical Chicane Dipoles (GW)

At Magnet Enterprises International in Oakland CA. They are bending the wings on the third coil of the 8 required for the IR machine. (Twelve more are required for the UV line)

• Return legs are ground to their final size. Top and bottom slabs are at the grinders. Field clamps are in process. Manifolds are in. Commercial parts are all in.

Injector Dipoles (DU/DV)

• Master Machine continues manufacturing.

• WANG NMR is shooting for a first wound GV Coil by next Tuesday.

Arc Dipoles (GY, GX, GQ)

• Proposals were received for the Bend (GX) and Reverse Bend (GQ) Dipoles. The proposals were evaluated. Questions requesting clarification were sent to several vendors.

• Wang NMR of CA continues making the GY coil winding mandrel and they are designing the potting mold for the GY coils.

• Bosma Machine has the GY core pieces in final machining. They are heat treating the return legs.


3 inch quad (QX)

• Eighteen QX Quadrupoles were qualified for installation in the machine by sign off by David Douglas. Four were delivered to the girder assembly area.

• Production measurements continued on the remaining QX Quadrupoles with no evident rejections.

Trim Quad (QT)

• Milhous Control of Virginia reports successful manufacture of a top coil. A full magnet should be wound by next week.

• The wire manufacturer took back the twisted material for re-spooling that removes the twist.

Sextupole (SF)

• DULY Research has a successful design using a longer magnet that minimizes saturation effects.

Octupole (OT)

• Work on this magnet is on furlough until the sextupole is designed.

Beam Line and Vacuum

• AES continues drawing up the chambers throughout the arcs.

• Design of the Arc Dipole Stands continued.

• Design continued on the details for the region after the cryomodules.

WBS 10 (Wiggler):

As reported last week, there was a 2 Gauss remanent field in the dispersion section which had not been present in previous measurements. This was traced to a mis-wiring problem when the magnet was first powered before the tests. The mis-wiring was corrected but the remanent field remained. Degaussing the magnet got rid of the field and measurements resumed.

WBS 11 (Optics):

We received the amplifiers and piezo actuators that will make the OCMMS test stand very nearly complete. We received some input on alternate ways to implement the feedback system for the fast steering, and after discussion, will work along the lines of an analog implementation (with digital readbacks). The drawing for the leadscrew for the optical cavity assemblies completed check and will go out for procurement soon. The drawing packages to date, plus icons for the other components, are being integrated in a complete system print. These drawings were collected into a presentation that was sent to our technical monitor (J. Albertine) and to C. Brau of the review committee, as a way to update them on the progress in optics. Accompanying this report was an update on the deformable mirror test results to date.

Procurement of the ultrafast laser has required some sheparding through the procurement process, but is moving forward. In our weekly meeting we discussed the design of an insertable mirror that would collect the FIR radiation due to the electron bunches from the injector for analyses of the temporal and phase characteristics. That design is moving forward. The preliminary drawings for one possible design of the 50 kW laser beam dump are nearly complete.