April through June

A. Project Summary


B. Detailed Reports

1.1 Magnets & Supports

1.2 Vacuum System

1.3 Power Supplies

1.4 RF System

1.5 Instrumentation & Controls

1.6 Cable Plant

1.8 Facilities

2.1 Accelerator Physics

2.2 Environmental Safety & Health


1. Technical Progress
On June 13-14, 2000, a DOE (Lehman) review committee conducted the third construction management review of the SPEAR 3 project. The charge to the committee was to examine the technical progress together with the cost, schedule, and management of the project. We are pleased to present the following excerpts from the Executive Summary of the committee report:


“The project team has made very good progress on the development of designs for the technical components and conventional facilities. This was especially true for the vacuum system. The accelerator design has matured as indicated by the thoroughness of accelerator physics analysis of the SPEAR 3 design. The magnet systems team was congratulated for a large volume of excellent planning and design. The magnets and girders appear to be sound and the production schedule looks quite realistic. There were some concerns by the committee that the girders do not have adjustable supports, and that the storage ring would require additional maintenance time to keep the ring aligned. In the areas of Power Supplies, RF Systems and Instrumentation & Control all appear to be moving along well and show evidence of close collaboration between SSRL and SLAC, which recently completed the PEP-II project successfully. The project presented an installation plan to the committee that had everything installed in eight months rather than the six months allotted by the shutdown schedule. Adequate time remains to work the installation schedule to allow for the appropriate planning and staging of technical components, and to adjust to the new funding profile.”

“The management structure and dedicated staff are in place to effectively execute the project. The team has implemented a Project Management Control System (PMCS) that was used on the PEP-II project. The project management understands its ES&H responsibilities. They are aware of ES&H policies and have implemented them to ensure ES&H is integrated into the planning of activities, and hazards are identified, evaluated and integrated.”

The new funding profile noted above was provided to the project subsequent to the review on June 21. We are in the process of establishing a new cost baseline and associated schedule in accord with the new funding plan.

The technical progress for this quarter is summarized below with details in Section B.

In the magnet program, the prototype dipole unit was completed and ready for magnetic measurements in April. Nanyang Li, SPEAR 3 magnet engineer, traveled to IHEP to oversee the final assembly phase and end-pole chamber details. Magnet group leader Richard Boyce together with Domenico Dell’Orco and Jack Tanabe visited IHEP in May to witness the final product and the results of the magnetic measurements. The IHEP measurements indicated that the field quality measurements were met. The prototype dipole was shipped on June 5 and arrived at SLAC July 6. Additional measurements will be made at SLAC to confirm the field quality of this first unit. The tolerances of the dipole laminations were verified previously and punching of laminations for production units is in progress.

The first laminations for the quadrupoles were received at SLAC in late June. Measurements here confirmed thatthe dimensions were well within the specified tolerances and approval was given to proceed with production of the laminations. Both dipole and quadrupole achievements are meeting the project schedule for magnets that was established last year.

The first machined top and bottom halves of the QFC vacuum chamber were received from the manufacturer in June. Tooling is near completion for production e-beam welding at SLAC which is planned for late July. The first machined components for the BM1 and BM2 units of the arc-raft chambers are also scheduled for July. Much effort is being devoted to the supports of these chambers which are in very close proximity to the magnet supports in most cases. Vacuum system designs are also underway for photon stops, titanium sublimation pumps, kicker magnets, insertion devices, and various bellows.

A purchase order was placed in April for the 1200 KVA dipole power transformer, which is actually two 600 KVA units in one enclosure. A successful design review for the overall dipole power supply was held in May. The goal is to have all design specifications ready for bid proposals in July. A design review was also held in May for the induction kicker magnet supply. Parts have been ordered and fabrication of the prototype unit will begin in August.

The order for four PEP-II style RF cavities and one PEP-II 1.2 MW klystron were placed last quarter. The cavity production in on track. Sample aluminum halves of the cavities were machined to verify lathe programming and the machining of actual copper cavity half sections has been initiated. Qualification samples by the manufacturer to verify the procedural steps are nearly complete. Efforts are in progress to improve the high voltage power supply design, the low level RF system, and the detailed design of the wave-guide system.

In the Instrumentation and Controls department, work has advanced on the specification and design of the computer control system, beam monitoring system, RF master oscillator, and the orbit interlock system. Work continues on cable plant details and schedule adjustments have been made to meet the requirements of the new funding profile.

Intensive efforts continued this quarter to finalize drawings and specifications for construction of new shielding walls and access mazes in the East and West straight section areas. The work is scheduled to begin July 7 with completion by mid-September. Contractor site walk-throughs took place in early May with bids required in mid-May. Unfortunately, only one contractor responded. The award was made in June at a price 450K$ above budget. This will result in the second CCB action for the project.

The accelerator physics group has focused on control system application developments. This has included graphical/interactive orbit control programs, fast feedback system simulations, pinhole camera development for vertical emittance measurements, and development of field uniformity requirements for vertical corrector magnets.

DOE/OAK has reviewed and approved SLAC’s equivalency request and find hazards analysis for SPEAR 3. The installation ofa new Very Early Smoke Detection Apparatus and the on-site fire department provide an appropriate level of fire protection as required by DOE Order 420.1.

2. Cost Reporting
Fig. 1 provides a summary of monthly direct costs through June 2000. Fig. 2 shows the integrated obligations and direct costs during this period. A comparison with planned (budget) costs and costs plus commitments is also given in Fig. 2. While the information in Figs. 1 and 2 is in terms of direct costs, Table 1 below provides a project summary total which also includes indirect costs.
Table 1
Project Costs (K$) through June 2000 
Direct Direct plus
Costs 5,422 6,323
Commitments 6,864 7,447
Total 12,286 13,770


Table 2 provides the BCWS, BCWP, and ACWP with associated cost and schedule variances through this reporting period. The variances are increasing as we are still reporting against the planned schedule and milestones for a plan for completion in FY 02. A new funding profile was provided by DOE on June 21 (following the Lehman Review) which provides additional funds for project completion in FY 03. We are in the process of establishing a new cost and schedule baseline which we will be tracking against in the coming months. The next quarterly report will reflect this revised project plan.

Table 3 provides a list and baseline schedule of Level 1 and Level 2 milestones for the project. All milestones scheduled for completion prior to the end of this report period have been successfully completed.


Figure 1

Figure 2

Table 3

B.Detailed Reports


1.1 Magnets and Supports

Supports System

Figure 3. SPEAR3 Standard Cell Girder

The support system designs have been ongoing. The preliminary review of SPEAR 3 magnet supports was held at SLAC on June 21, 2000. The girder design is being modified to allow for the new layout of vacuum chamber supports. The purchase order for support rod ends of dipole, quadrupole and sextupole prototypes has been issued.

The Lehman Review held on June 13-14, 2000 concludedthe following: “The SPEAR 3 team is to be congratulated for a large volume of excellent planning and design. The magnets and girders appear sound and the production schedule looks quite realistic. The decision to use three girders per sector is a good one and will facilitate installation. The fact that the girders do not have adjustable supports adds some risk that extra ring maintenance time will be needed to keep the ring aligned, especially since a new floor will be poured just a few weeks before the start of girder installation. However, the compensatory benefit is that the SPEAR 3 girder is extraordinarily rigid, with all vibrational resonances above 20 Hz in frequency.This should be very beneficial for orbit stability. The six-strut system of magnet supports will minimize the added effort necessary to re-level the ring by moving every magnet”.

IHEP received all the copper conductors purchased by SLAC, manufactured by Outokumpu in Finland and insulated by Van Roll Isola in Switzerland (quadrupole only).IHEP received the steel necessary for the dipole production magnet. In May, R. Boyce, D. Dell’Orco, N. Li and J. Tanabe visited IHEP to inspect the dipole magnet prototype and review the measurements. The results of the visit were very positive and SLAC/IHEP ICA Attachment 1 was reviewed and agreed upon. IHEP completed the 145D Gradient Dipole prototype magnet construction and shipped it on June 5, 2000.


SLAC shipped to IHEP the first batch of water fittings and hoses to be used for the production magnets. IHEP and SLAC solved the technical problems experienced during the soldering of water fittings to the copper conductor and the Devcon injection in the dipole laminations. IHEP has begun punching the dipole laminations for the production magnets.

The revised design of quadrupole magnet 34Q-3 was introduced to allow the installation of the vacuum pump port at the QF1, QFZ-A and QDX-B locations. IHEP completed the drawings of all the dipole, quadrupole and sextupole magnets variations.

Figure 4. End view and back view of the gradient dipole magnet. Pictured are the LCW manifolds and hoses, bus connections between the upper and lower sets of coils, and terminals for thermal switches and trim coil connections.

Figure 5. Group picture of IHEP magnetic measurements group and SLAC in Beijing

Magnet measurements
The magnetic measurements of the Gradient dipole prototype were performed at IHEP using a Hall probe and the newly designed translating coil. Three different sets of chamfered inserts were tested to reduce the nonlinear components of the integrated field across the good field region.

Figure 6. Translating coil setup for the magnetic measurements at IHEP

Figure 7. Close-up view of the chamfered pole insert for the 145D prototype

The 2D field quality results obtained with the Hall probe are in very good agreement with the 2D Ansys calculations and within the SLAC specifications for good field (DB/B < 2 ´ 10-4 at 30 mm from the beam and 3 GeV).

Figure 8. 2D Hall probe measurement results: DB/B < 2 ´ 10-4 at 30 mm from the beam (-46.6 mm < x < 46.6 mm) at 630 A and 3 GeV

The integrated field quality measurements performed with the translating coil were used to iterate the profile of the chamfered pole inserts. The second iteration in chamfer profile met all the magnetic field specifications issued by SLAC.

Figure 9. Compensated translating coil measurements results. The average value of DB/B along the beam trajectory(-46.6 mm < x < 46.6 mm) at 630 A - 3 GeV is less than´ 10-4

IHEP manufactured 2 rotating coils that will be used in the magnetic measurements of quadrupoles, completed the quadrupole die and punched 3 test laminations. The CMM measurements performed by IHEP on the quadrupole laminations met SLAC specifications and the laminations were sent to SLAC for confirmation.


1.2 Vacuum System 

During this quarter, the efforts of the vacuum group have been the following:


¨  Integrate standard chamber design and supports and complete the standard girder chamber design details,

¨  Complete the detail design of the assembly/electron beam (EB) welding tooling,

¨ Complete fabrication of the QFC chamber assembly tooling and start the fabrication of the BM-1 and BM-2,

¨ Begin first article fabrication of the QFC chamber,

¨ Complete the conceptual design of the standard girder vacuum supports,

¨ Continue TSP testing,

¨ Complete the conceptual design for the injection kickers,

¨ Start the design of RF cavity straight chambers,

¨  Continue work on the conceptual design of Beamline 11 (BL11) transition/bellows module.

Work has continued on completing the standard girder drawings.All of the piece part and assembly drawings are in final check and work on finalizing the documentation is near completion.Also, design and detail drawings of the electron beam welding tooling for all the standard chambers are complete.The QFC EB weld tooling was fabricated this quarter and the BM-1 and BM-2 EB weld tooling will be complete next quarter.Due to the new 3-D parametric modeling system and the delay in producing an operational database system, a temporary release procedure is in use.Setting up a manual release system has led to delays in releasing drawings.

Figure 10. QFC EB Weld Tooling

Also, design and detail drawings of the electron beam welding tooling for all the standard chambers are complete.The QFC EB weld tooling was fabricated this quarter and the BM-1 and BM-2 EB weld tooling will be complete next quarter.Due to the new 3-D parametric modeling system and the delay in producing an operational database system, a temporary release procedure is in use.Setting up a manual release system has led to delays in releasing drawings.

The majority of piece parts to produce the QFC vacuum chamber were received this quarter.The machine halves were received in early June.After the chamber halves were dimensionally inspected, they were assembled with the sidewalls using the EB tooling fixture.Measurements of the assembled chamber were taken to provide systematic information of chamber deformation during each assembly stage.This information will help define the assembly procedure and potentially eliminate some of the fabrication steps.During the next quarter, the remaining fabrication steps will be performed with systematic inspection data. Currently a mechanical straightening fixture is being developed and the plates will be straightened before any welding.Two sets of plates for the BM-1 and BM-2 machined halves are currently being machined and are expected to be delivered to SLAC in July and August.

Figure 11. Production Machined Plates

Delivery of the SPEAR3 beam position monitors (BPMs) is approximately 2 months behind schedule.The vendor had difficulty locating the stringer free copper-nickel alloy.Also, the company relocated their manufacturing facilities from Colorado to Connecticut.The change in the production facility and some staff has led to delays in the manufacturing of the BPMs.SLAC has provided their purchasing experience to help locate the material.The SPEAR3 project also changed the sequence of welding the BPMs into the standard chambers to minimize the impact on schedule due to the late delivery.

Significant progress was also made during the last quarter on the supports for the standard girder chambers.  The compact magnet lattice required close integration between the vacuum, magnet and girder designs.  Several iterations of the vacuum chamber supports were required to create a design that could meet the space constraints.  The conceptual design and structural calculations were completed and a conceptual design review was held on June 21, 2000.  The conceptual design was approved and work on the action items and finalizing the design will continue through next quarter.

Figure 12. Standard Girder Support

Pump testing on the conceptual design of the titanium sublimation pump demonstrated that the titanium sublimation coverage was less than anticipated.  This lowered the capacity of the pump and decreased the time required between titanium sublimation.  A simple modification was made to the pump to increase the surface area and line of sight for sublimation of titanium.  Detail drawings and fabrication of a new TSP was completed this quarter and testing will start next quarter.  Further design changes may be required in order to meet our design goals.

A conceptual layout of the RF straight was completed this quarter.Ray trace studies were performed and mask locations were defined based on estimated acceptable values for synchrotron radiation deposition.Analysis on the masks and pumping are pending.Conceptual designs for the higher-order mode drifts and the RF mask/pump module are near completion.Also, the conceptual design and analysis of the RF bellows module was completed.

Work on the insertion device transition modules were put on hold this quarter to shift manpower to the standard girder chambers.Some progress was made earlier in the quarter to finalize the conceptual design of the BL-11 mask-transition-bellows module.Design and analysis work should restart late next quarter.

Significant progress was made on the injection kicker design.A conceptual design review was held on May 17, 2000.The vacuum group presented the vacuum/magnet design of the kicker for the 1.2-m and 0.6-m long DELTA style kickers.Impedance and magnet calculations were performed and the design was optimized.The design review resulted in approval to build a prototype 1.2m long injection kicker.The prototype magnet will be built by September 2000.Detail drawings for the injection kicker are in progress.

1.3 Power Supplies

DOE/NIH June 13th and 14th Review

The Magnet Power Supply report given during the June 13 and 14th DOE/NIH project review described work priorities, status, progress and near-term planning. The report also emphasized the role of the SLAC Power Conversion Department, the participation of which is key to minimizing technical and scheduler risks for the Dipole Power Supply, bipolar power supplies and Kicker Pulser. The report was well received by the reviewers and no action items were generated. The reviewer’s only comment was a commendation for the extent of cooperation and collaborative effort between SLAC and SSRL.
Dipole Power Supply
In April a purchase order was placed for the 1200kVA Dipole Power Transformer with the Neeltran Corporation, located in Connecticut. The purchase was on schedule and within budget. The “transformer” is actually 2-600kVA transformers housed in one enclosure. The transformer will provide the 6-phase AC power needed for the 12-pulse Dipole Power Supply. In June Neeltran submitted mechanical drawings of the transformer for SSRL review. ( Figure 13). Subsequently, SSRL’s comments were returned to Neeltran for incorporation onto the drawings. The transformer flux density, inrush current and seismic analysis required for manufacture release are due for submittal by Neeltran.

A successful design review for the Dipole Power Supply was held on May 24th. No major problems surfaced and the buck regulator topology (shown in Figure 14) was accepted as proposed. However, several minor issues did arise. These review issues are being investigated/resolved and those that are appropriate will be incorporated into the Dipole Power Supply Specification that is currently in preparation. The goal is complete the specification and have it suitable for bid purposes by the end of July. Industry is also being canvassed in an attempt to locate potential manufacturers that are qualified and have the capability and interest to design and fabricate the rather large 930kW Dipole Power Supply.

Bipolar Power Supplies

The 20 Eurocard crates that will house the bipolar power supplies and their multichannel controllers used for power supply control have been received from Byra, a design and manufacturing firm located in New Mexico. The crates will be inspected and bench tested by the SLAC Power Conversion Department. Shown in Figure 15 is one of the actual SPEAR 3 bipolar power supply/multichannel controller crates mounted in the Bipolar Power Supply Certification Test Stand.

During the next quarter, work will begin on the fabrication and testing of 8 prototype bipolar power supply boards. A comprehensive test series is planned, focusing on electrical and response performance, thermal performance, EMI spectral analysis and crosstalk immunity.

Kicker Pulser

A very successful design review of a new solid-state induction kicker was held on May 24th. A new topology, described in the last quarterly report was presented for detail examination. The new topology is based on a mature (ongoing for more than 2 years) R & D collaboration between the SLAC Power Conversion Department and the Lawrence Livermore National Laboratory for the Next Linear Collider Modulator Project. On the basis of a successful presentation, reviewers recommended that the Power Conversion Department proceed immediately with purchase of parts for a full-power prototype kicker pulser based on K2 magnet requirements. The schematic diagram of a typical kicker pulser is shown in Figure 16. A 4-stage pulser rated 7.5kV, 2.6kA is needed for K2 while an 8-stage pulser rated 15kV, 2.4kA is needed for the K1 and K3 magnets. During this reporting period a considerable portion of the needed prototype parts were ordered. The remaining parts will be received and fabrication of the prototype started during the next reporting period.

Considerable modeling of the kicker magnets and the pulsers has been done with the PSPICE circuit analysis program. Below is a PSPICE generated waveform of the current in the K2 kicker magnet. The displayed current pulse has the required amplitude and shape.

Single Channel Power Supply Controllers

As described in the April-June 2000 quarterly report, some the parts that crucial to the single channel controllers and which might be future short supply are being researched for availability and some have already been purchased. Specifically, the parts are the Intel 8044 controller, the ADCs and DACs and a custom +/- 15V power supply. The intent of the early purchases is to ensure that the PEP II type controllers can be fabricated without expensive changes or re-engineering.

Figure 13. Dipole Power Transformer Outline

Figure 14. Dipole Power Supply Topology

Figure 15. Mutichannel Controller Eurocard Crate In Certification Test Stand

Figure 16. Induction Kicker Pulser Schematic Diagram


1.4 RF System

The new RF system layout using a single high power klystron driving the 4 RF cavities is being finalized. A new location for the klystron and controls part of the RF station was chosen within the building covering the West-Pit. This location greatly simplifies overall RF system layout by bringing the klystrons close to the chosen cavities position in the tunnel. A new 2MW klystron power supply will replace the standby existing 860 kW power supply. The pre-installed klystron, control electronics and power supply can be commissioned early while SPEAR 2 is still in operation.

A Change Control Board (CCB) review was held and the new CCB#1 was approved. With this action the new RF system layout and the new klystron location were accepted.

Fabrication of 4 RF cavities at Accel Instrumentation in Germany is making good progress. The process qualification samples are essentially complete including the machining of the cooling channels in an aluminum model. Preformed copper bowles for the cavity body have been provided by SLAC and the inner and outer contours have been machined. The next process is the joining of two cavity halves by an equatorial weld. (Delivery of the cavities is scheduled for Fall 2002). Fabrication of cavity accessories at SLAC like ceramic windows and higher order mode loads is about 90% complete.

The 1.2 MW klystron was ordered March 17, 2000 from Marconi Applied Technologies with a 12 months delivery time. This company is also providing the replacement klystrons for PEP-II. The associated waveguide layout design is 90% complete and drawings are expected to be signed off next quarter.

The Low-level RF System was reviewed and design modifications have been started. A modification to the Ripple Feedback Loop in the main RF module is also being considered for a PEP-II upgrade. Several chassis like the Local Control Panel and the Tuner Driver Chassis have already been built. The Process Logic Control system for interlocks and status readbacks has been ordered and received. Component procurement for other modules and chassis’ is under way.

1.5 Instrumentation and Control Systems

Work by the SPEAR 3 Instrumentation and Control (I&C) group during this quarter has focused on the continuing specification and early design of computer control, BPM processing, timing and protection system components.Progress for various systems is provided below.

Computer Control System 

·  An EPICS-trained software development engineer began work in June.
·  Two Power PCs have been ordered for initial development of EPICS IOC and Orbit Feedback processing functions. We have received several Wiener smart VME crates that will be used for these systems. Preliminary tests using these components and the VxWorks real-time operating system will proceed over the next quarter.

· Work is progressing on the design of the fast digital power supply controller. ADC, DAC and CPU component candidates have been identified and ADC evaluation boards have been ordered. Digital regulation and filter algorithms for power supply control and monitoring will be specified in the next quarter in order to select a CPU appropriate for the controller. Digital control of the power supply pulse-width modulating units, which would eliminate the need for DACs, will also be considered.

Beam Monitoring Systems 

·  Design of the BPM RF/IF Converter modules is continuing. A possible development collaboration with Bergoz, Inc., is being considered. A decision to proceed with an in-house design or to pursue the collaboration will be made in the next few months.
·  The first 2 IF Digital Receiver modules from Echotek are due for delivery by the end of July. They will be tested in August using a Power PC running VxWorks and a board support software package provided by the vendor.

·  The BPM Timing/Crate Driver module will be completed after receipt of the Digital Receiver module (to assure proper connector choices) and the first unit is planned for fabrication in the next quarter.

·  An orbit feedback simulation model is being developed on MATLAB Simulink. The ControlShell software development tool from RTI has been purchased; ControlShell takes MATLAB model programs and generates VxWorks code that actually implements feedback routines. The engineer responsible for this work (and for Timing System components) has left SLAC and a replacement engineer is being sought from within SLAC.

·  The BESSY II mechanical design for the image current-carrying shroud for the DCCT will be adapted for SPEAR 3.

·  The design for the UV and visible light synchrotron light mirror has begun.

Timing System 

·  A PTS DDS-based signal generator has been ordered that will serve as the SPEAR 3 RF master oscillator. The unit has very low phase noise and phase-continuous frequency switching.
·  Procurement specifications for the LO/Clock and Booster-SPEAR Phase-Locked Loop systems are nearly complete and an order to Wenzel, Inc. for a the systems is planned during next quarter.

Protection Systems 

The design of the Orbit Interlock has begun. A pair of BPM processors and associated support hardware will be purchased for test from Bergoz, Inc. Interlock processing CPU options are being considered, with VME-based PowerPC modules being a likely candidate.

1.6 Cable Plant

Progress continues to be madeon technical design of the Cable Plant, principally the cable tray design.Preparation for shutdown FY 2000 work was completed.

Details of the enclosure Cable Tray design continue to be identified.The cross-section of the standard cell, indicating cable tray and piping dimensions, is being optimized.The Cable Tray that carries water-cooled bus may need to be reduced from 6” to 4” height.To determine the suitability of this change, the cable fill factor and electrical codes are being reviewed.

Cable Tray material required for the standard-cell mockup was located on-site, and installed in the mockup.Since the amount of on-hand material was limited, an order has been placed for the additional material.The cable tray mockup is intended to exactly model the configuration to be used inside the enclosure, including all width transitions, tray drops, and ground wire bonds.

An upgrade of Equipment Cabinets (Relay Racks) in the SPEAR Main Control Room (MCR) is underway.This is a SPEAR infrastructure (Accelerator Improvement Project) upgrade that is essential to SPEAR3.The project consists of early removal of unused cables, increasing the size of the Control Room work area, increasing available console space, modernizing the relay racks with eleven new racks, and decreasing ambient noise.The MCR is also receiving new general-purpose duplex outlets.

This improvement project was guided by inputs from the Operations, Accelerator Development & Controls, and Accelerator Physics groups.Several plans were developed and the best of these plans was selected for implementation.

Phase I of the improvement is being completed during shutdown FY 2000.In Phase I three new racks are added, equipment relocated, and old racks decommissioned.The racks and electrical supplies are ordered and are due in July.An earthquake resistant support frame has been designed, peer reviewed, and is in fabrication.Phase II is scheduled for shutdown 2001.These infrastructure improvements will facilitate the installation of SPEAR3 control electronics in the MCR.

1.8 Facilities

The bids for the construction of the new shielding walls and mazes in the West and East straight sections were opened on May 16th. See the last quarter (Jan-March) report for layout drawings of the modifications. The only bid submitted was 72% higher than the Engineer’s Estimate. A second effort to invite more potential bidders to re-bid the project again resulted with the same bidder from the first bid. The lack of interest from potential bidders and the high bidding price are believed to be result of the fertile economy in the San Jose silicon valley area.Subsequently, the subcontract was awarded on June 3rd.The project kickoff meeting was held on June 8th.The construction is scheduled to commence on July 10th and be completed on September 15th.The engineering is at 100% completion and the design drafting is at 95% completion.


2.1 Accelerator Physics

During the third quarter of FY 2000, efforts of the accelerator physics group were concentrated on control system application development and support for machine engineering issues.

Accelerator Simulator

An accelerator simulator has been developed in the MATLAB software environment. Component modules include drift, dipole, quadrupole, sextupole, multipole and rf cavities. Particle transport through each element is accomplished with fourth order symplectic integration. Other techniques are readily available. From MATLAB, transport simulations are performed by referring to a digital link library (DLL) of c-commands to process mathematical expressions at top speed. Studies have been made to optimize performance with the result that c-code ring-tracking routines automatically access c-code element tracking routines without deferring back to the MATLAB work space. The result is approximately a factor of 20 speed-improvement and 3-4 orders of magnitude improvement relative to direct MATLAB calculations. With a 600 MHz computer, particle tracking now proceeds at roughly 0.1% the speed of particles in the real accelerator.

The complete accelerator simulation library is being assembled in the format of a MATLAB 'toolkit' (nominally a commercial product) to facilitate code maintenance and sharing with sister DOE laboratories. A web site is under construction to facilitate access to the code and provide information about the code. Based on the underlying particle transport simulation modules, higher-level physics applications have been developed. An example is the coupled-lattice betatron function calculation based on theory developed at Cornell.

Simple Channel Access

The Simple Channel Access (SCA) protocol developed at Lawrence Berkeley Laboratory (LBL) has been compiled at SSRL and can now be used to communicate with the SPEAR/ALHPA control computer. SCA allows machine physicists to access and deposit information in the SPEAR 3 database using the EPICS control system toolkit (Channel Access). Recently, the ALPHA computer was configured to host the SPEAR control system, and SCA placed in the Digital Link Library for MATLAB. On July 7, communication was established between MATLAB and the ALHPA computer. This marks a major milestone in demonstration of MATLAB as the software language of choice to develop complicated accelerator application programs for SPEAR 3. With the communication path established, prototype application codes will be tested on SPEAR 2 to ensure efficient deployment on SPEAR 3.
Orbit Control Application Program
Further progress was made on the graphical/interactive orbit control program planned for use with SPEAR 3 (see Figure below). At present, most of the mathematical algorithms and the control g.u.i. are in place. The remaining work will be directed toward file-handling and refining the Simple Channel Access database connection as described above. Tests will be carried out on SPEAR 2 as soon as all the control system parameter-server software is complete. The Orbit Control application program is being tested in parallel on the CAMD light source in Louisiana.



Figure 17. Graphical Orbit Control panel for SPEAR 3.
This system will be tested on SPEAR 2 in the Fall of 2000.

External Program Driver from MATLAB

MATLAB software has been developed to externally drive the accelerator design program MAD (Methode Accelerator Design/CERN) from MATLAB. The advantage is that MAD contains complex software routines for fitting optics parameters that would require expensive effort reproduce in MATLAB. Using the MATLAB data-handling and graphical interface capabilities, the combined systems provide a powerful means to develop control-room ready accelerator control applications. Studies of top-up injection mode for SPEAR 3 have been carried out using the combined MATLAB/MAD accelerator simulation environment.
Fast Feedback Simulations
Fast feedback simulations have been initiated in SimuLink (a MATLAB tool box) to study corrector power supply stability and corrector field uniformity requirements. The SimuLink studies have also begun to investigate the use of modern control algorithms which achieve feedback performance exceeding the standard '3-parameter' feedback technique used at most accelerator laboratories. Initial results indicate the optimized algorithms out-perform the standard techniques when sensor noise is present. The control algorithms were then transferred to a commercial 'ControlShell' development environment. ControlShell is intended to facilitate development and deployment of moderate-to-large scale control systems such as the orbit feedback system for SPEAR 3. Studies to determine the practical extent for use of ControlShell in the SPEAR 3 feedback system will continue into the next fiscal year.
Pinhole Camera
A pinhole camera has been developed the measure the vertical emittance in SPEAR 2, and to develop technology for the SPEAR 3 synchrotron light monitor. The pinhole camera system images hard x-rays from a bending magnet source through a 30x25 micron 'pinhole' onto a photo-luminescent screen. The detector consists of a YAG phosphor screen, a Si mirror, a magnifying lens and a Pulnix TM745 CCD camera. Limborg, et al, published detailed results of the image data in the 2000 European Particle Accelerator Conference (EPAC 2000). A new version of the pinhole hardware, designed to accept power densities delivered by SPEAR 3, is in the engineering phase. This device will be transferred to SPEAR 3 during the 6-month installation phase.
Photon Beam Steering Envelope
The photon beam steering envelope for SPEAR 3 was revised to include power limitations presented by components in the photon beamlines. The steering envelope dictates safety parameters for the fast orbit interlock system (MPS). Conditions under which the interlock system must be active include:

1. When any beamline is OPEN, the associated beamline interlock must be ACTIVE for all currents. This protects sensitive beamline components against either dipole or insertion device radiation.

2. When any beamline is CLOSED the associated beamline interlock must be ACTIVE for beam currents >20 mA. This protects the main copper chamber against excessive insertion device radiation power.

3. When all beamlines are CLOSED and all insertion devices OPEN, specific interlocks must be ACTIVE above a to-be-specified beam current to protect existing insertion device vacuum chambers. Note that all new SPEAR 3 hardware will tolerate a dipole radiation strike with up to 500 mA circulating current.

Vertical Corrector Field Specification

Studies were carried out to verify that 750 micro-radian vertical corrector kicks are adequate for closed orbit and local-bump considerations. For closed orbit control, simulations show rms corrector strengths of about 100 micron radian will correct the closed orbit down to about 100 micron. A single 750 micron single corrector kick will generate approximately 2.5 mm closed orbit deflection, sufficient for feedback and machine modeling purposes. Four magnet bumps across insertion device straight sections are sufficient to produce orbit deviations of up to 3.5 mm or almost 1 mrad in the vertical plane (see Figure below). We conclude the 750 micro-radian corrector design will be adequate for SPEAR 3 steering requirements.


Figure 18. Phase-space area accessible by 4-magnet bump with maximum vertical corrector strength of 750 micro-radian spanning across an insertion device straight.

2.2 Environmental Safety and Health

This quarter has seen many of the Environmental, Safety and Health issues or concerns raised about the upcoming shutdown construction activities, resolved to the projects satisfaction. Finalization of the scope of the work plan, also allowed closure on outstanding reviews and approvals. As examples, the Radiation Physics Group conducted a peer review of the West & East Pit and Beamline 2 Alcove modifications and unanimously approved the proposed changes. While the final results from the environmental sampling plan did identify a few concrete samples with elevated levels of PCB’s and Lead, ground or dirt samples turned up clean. As a precautionary measure, all materials being removed this shutdown will be disposed of through the Hazardous Waste Management group who have much experience with this type of construction/excavation activity.

The Preliminary Fire Hazards Analysis was reviewed and approved by the relevant SLAC personnel and submitted to the DOE site office, along with a request for a “Permanent Equivalency” for non-compliance of SPEAR 3 with the provisions of automatic suppression system (fire sprinklers) in the accelerator housing. Approval by the DOE of the PFHAD and issuance of the “Permanent Equivalency” was given in June.

The Preliminary Safety Assessment Document (PSAD) continues on track for completion by the end of this calendar year. A draft document outlining the required citizen committee reviews of project systems and sub-systems has been presented to the SPEAR 3 management.

Open communication with relevant ES&H groups and individuals continues in an effort to provide everyone with a working knowledge of upcoming activities and in keeping with the ISMS philosophy.