12 GeV Updates
December 22, 2010
Contracts have been awarded for the dipole magnet and the second and third quadrupole magnets for the Super High Momentum Spectrometer for Hall C. All three magnets are of the "warm iron" type; separate contracts for the associated steel yokes will be placed in fiscal year 2012. The second coil for the horizontal bend dipole magnet at the front of the SHMS has been wound at Michigan State University. The first thousand meters of the copper stabilizer that is soldered to the superconducting cable has been extruded, with the balance to follow soon, and the contract for the soldering step is now awarded. Assembly of the first two of five cryogenic control reservoirs for the SHMS magnets is nearing completion at the vendor.
December 8, 2010
Seventy of the total order of 86 niobium cavities for the 12 GeV cryomodules have been received. Welding has been completed of the helium vessels onto the cavities for the first 12 GeV cryomodule. Thirty-one of the total order of thirty-six 4-meter dipole magnets for the beam transport lines have been received; testing of those magnets continues. All beam transport quadrupole magnets have been received and accepted. Forty-five RF circulators/isolators have been received. The results from the klystron-circulator/isolator testing found that the second harmonic amplitude is less than -40 decibels of the fundamental mode’s power; that result simplifies the design of the second harmonic filters that will go into the waveguides between the isolator/circulators and the cavities. The request for proposals was released for the purchase of two hundred and sixty 20 Amp/70 Volt power supplies for the beam transport quadrupole magnets and corrector dipole magnets.
December 1, 2010
12 GeV installation planning for the upcoming six-month accelerator shutdown (May – November 2011) incorporates transfer of 12 GeV equipment ownership, as appropriate, to the Accelerator Division. Related equipment documentation, training and commissioning plans are being developed to ensure smooth integration into the existing accelerator. 12 GeV participation in weekly labwide integrated schedule meetings continues to ensure effective communication and optimized installation work planning.
November 24, 2010
Metal wall panels for Hall D have been installed, and the construction contractor is installing flashing. Overhead doors for the Hall D truck ramp are being installed, and the electrical finish work is near completion. The photon beam dump is complete. The design team conducted substantial completion inspections Tuesday. The ready-for-equipment inspection is scheduled for Nov. 30, with representatives from 12 GeV management, the Hall D Group and the ESH&Q Division. The Hall D Group has drafted a conduct of operations document for the initial equipment installation work. This document includes the interface requirements, since the construction site will be dual occupied by JLab staff and the civil construction contractor following the RFE.
November 17, 2010
The intermediate manufacturing readiness review for the solenoid magnet and the final manufacturing readiness review for the torus magnet for the Hall B CLAS12 spectrometer were held at the vendor, Wang NMR. The wave-shifting fibers for the pre-shower calorimeter (PCAL) are arriving, the extruded scintillator is being cut, and lead sheets and box parts are arriving, all in anticipation of starting assembly of the first PCAL sector in the coming spring. Stringing of the last sense wires is ongoing for the first sector of the region 2 drift chamber for CLAS12, and the second assembly line, at Old Dominion University, is now set up and ready to go. Thirty-eight (of 48) of the five-inch-diameter, quartz-face photomultiplier tubes have arrived for the high threshold Cerenkov counter and are being tested.
November 10, 2010
Delivery of the niobium cavities for the cryomodules has ramped up, with 34 of the final 86 now onsite. The vendor for the warm helium compressor skids needed for the new Central Helium Liquefier (CHL-2) has taken delivery of the compressors. The first 20 of the radiofrequency system’s waveguide circulators have arrived onsite. The first of the new 2.5 meter curved dipole magnets for the new west spreaders and recombiners have been shipped. Ion pump supplies for beamline vacuum are arriving in quantity.
November 3, 2010
12 GeV installation plans for the 2011 six-month accelerator shutdown (mid-May through mid-November) are being finalized and incorporated into the lab-wide integrated schedule. Weekly cross-divisional meetings are being held to identify and resolve potential conflicts with work or shared resources. Hall D equipment installation planning continues as the scheduled ready-for-equipment (RFE) date of Nov. 30 approaches.
To coordinate 12 GeV Project needs, the JLab Facilities Management and Logistics group has developed an online database for related space and storage requests, including offsite rentals. Coordination of material handling and transportation equipment continues in order to appropriately support the safe completion of installation activities. The 12 GeV team has developed a project work order system that is integrated with the existing Facilities work request system.
October 27, 2010
The North and South Access Building additions and power upgrades to support the accelerator operations at 12 GeV are complete. Ready-for-equipment (RFE) inspections were conducted on Oct. 14 and 25, including representatives from 12 GeV management, Facilities Management & Logistics and ESH&Q. The cooling towers and pumps for the Central Helium Liquefier utility upgrades are set in place, and the subcontractor is installing the associated piping. Metal wall panels for Hall D were delivered to the site on Oct. 25, and installation will commence this week. Accelerator group welders are completing the leak test on the portion of the beam pipe entering into the photon beam dump at Hall D.
October 20, 2010
The fourth group of four barrel calorimeter (BCAL) modules for Hall D has arrived at JLab from the University of Regina, Saskatchewan, Canada, meaning one-third of all the modules are on-site. The first units of the new Cockcroft-Walton type high-voltage synthesizer-and-divider bases for the Hall D forward calorimeter passed acceptance tests at Indiana University, thus 500 of the total 2800 have been ordered to start mass production. Tests of first-article preamplifiers for the central and forward drift chambers, using the custom application-specific integrated circuit developed in collaboration with the University of Pennsylvania, were completed successfully. Therefore, all key elements of the electronics chain for the Hall D tracking detectors are now entering mass production. Manufacture of the custom 16-channel 250 Megahertz flash analog-to-digital converter, key to calorimeter, time-of-flight array and tagger hodoscope readout, has also begun, with assembly of the first 20 production boards. The largest of the Hall D solenoid magnet coils has been installed in the Test Lab stand and is being prepared for cool-down and full-field tests later this fall.
October 13, 2010
The klystron has demonstrated full power, continuous wave operation; gain and bandwidth are improved over what was measured on the first unit. New delivery schedules for the klystrons and cathode power supplies have been received from the vendors and incorporated into the Project status schedule. Twelve niobium cavities for the 12 GeV cryomodules have been received; the vendor has provided an updated schedule which shortens the overall delivery timeline by six months. Deliveries of the 4-meter dipole magnets for beam transport have reached 22 of the 36 in the contract. More than 40 of the corrector dipole magnets have been received.
October 6, 2010
At the request of the Office of Nuclear Physics, Daniel Lehman, Director of the Office of Project Assessment in DOE's Office of Science, convened a team of 22 experts plus nine DOE observers in an Independent Project Review of the 12 GeV Upgrade at JLab Sept. 28-30. The purpose of the review was to assess progress in all aspects of the project since April 2010. The review committee concluded that the project is making satisfactory progress and provided 21 recommendations to guide activities in the coming months.
Many 12 GeV installation tasks were completed during the summer 2010 accelerator shutdown, including the low-conductivity water piping in the west arc, electrical conduit and cables for the 10 new zones, the remaining two cryomodule base plates in the South Linac, and the Arc 10 pedestals. In addition, a master oscillator was replaced, magnet quality controls were checked and related cables were labeled, and core drilling was done for power-system cables. Lessons learned during this shutdown are being used to refine plans for installation work during the six-month shutdown scheduled to start in May 2011.
September 15, 2010
Facilities Management & Logistics personnel are preparing solicitations for two 12 GeV civil procurements. The FY11 procurements include work to be performed during the six-month accelerator shutdown. One will involve the low conductivity water systems in the North and South Access Buildings, which will be upgraded to increase the capacity. The water will be drained from the LCW systems to facilitate reconfiguration of the piping. The design review for this procurement package is scheduled for Sept. 17. The second FY11 procurement includes two new penetrations into the tunnel at the beam switchyard. During the FY10 summer Scheduled Accelerator Down, the locations of these penetrations were identified by representatives from Facilities Management & Logistics, Survey & Alignment, Accelerator Operations and Accelerator Power Systems.
September 8, 2010
The status of detector systems for the Hall C Super High Momentum Spectrometer was reviewed at a day-long meeting on Aug. 26. Over half of the slats for the three scintillator hodoscopes are assembled and being tested. Procurement of the bars for the quartz hodoscope is progressing. Preparations are underway for the heavy gas Cerenkov counter. The support frame for the pre-shower part of the lead-glass calorimeter has arrived and is being readied for stacking of the modules. The production drawings for the spectrometer support structure now incorporate a 20-ton weight reduction after further study of the deflections when loaded with the magnets.
September 1, 2010
The klystron vendor has successfully demonstrated 13 kilowatt output from the initial klystron. This was a significant event for the radiofrequency system’s success. The required operating parameters have been transmitted to the vendor for the power supplies for the klystrons. The first new dipole magnet for the beam transport spreaders and recombiners has been received. Five additional 4-meter beam transport dipole magnets were received, which brings the total delivered to 17 of the 36 in the contract. The 12 GeV accelerator installation work during the current accelerator shutdown is going extremely well. Low-level RF fabrication and Central Helium Liquefier installation activities continue to be ahead of schedule. Testing of the first two niobium cavities for the cryomodule production was suspended while modifications to the Test Lab are being made as part of the TEDF project.
August 25, 2010
The summer 2010 accelerator shutdown started Aug. 13 and is well underway. The shutdown includes many 12 GeV Upgrade tunnel installation tasks. Tasks completed to date include: installation of two-inch low conductivity water piping in the west arc, replacement of the master oscillator, emptying of cable penetrations for the new zones, installation of three zones of electrical conduit for cables, placement of forms for the remaining two cryomodule base plates in the south linac, and layout of Hall D/Arc 10 stands. Remaining installation tasks include installation of the five-, four- and three-inch low conductivity water piping in the west arc and installation of electrical conduit and cables in seven of the new zones.
August 18, 2010
There is a great deal of 12 GeV civil construction activity in progress. In the accelerator tunnel, installation of the low-conductivity water (LCW) header pipe for the 10th arc commenced with the start of the summer Scheduled Accelerator Down. At the North and South Access Building additions, the sitework is being completed with asphalt paving. At the Central Helium Liquefier (CHL) building addition, the underground portion of cooling water piping for the CHL #2 compressors is being installed from the cooling towers to the west end of the new addition. Also, SEG blocks for the Hall D photon beam dump and electron beam dump are being transported to the Hall D construction site. The concrete roof for the Hall D truck ramp has been placed.
August 11, 2010
The intermediate manufacturing readiness review for the torus magnet for the Hall B CLAS12 spectrometer was held in July at the vendor, Wang NMR. Short sample tests of the superconducting cable for the solenoid magnet were completed successfully at the University of Twente, the Netherlands, and the cable was shipped to Wang NMR. The production of the extruded scintillator for the Pre-Shower Calorimeter (PCAL) for CLAS12 concluded at Fermilab, and orders were placed for the PCAL wave-shifting fibers by The College of William & Mary and JLab. Stringing of guard wires and field-shaping wires was completed for the first sector of the CLAS12 Region 2 Drift Chamber. This first sector is being built as a joint effort among Old Dominion University, Idaho State University and JLab. A contract has been readied for ODU to string the remaining five Region 2 sectors. Molds were machined at JLab for the mirror production for the CLAS12 High Threshold Cerenkov Counter (HTCC). Seventeen (of 48) of the HTCC five-inch diameter quartz-face photomultiplier tubes have arrived and are being tested. For a Forward Time-of-Flight wall, a series of tests of candidate photomultiplier tubes and scintillator material were concluded with the participation of the University of South Carolina.
August 4, 2010
The first two niobium cavities for cryomodule construction have been received from the vendor; inspection of those units has begun. Nine of the cryomodule helium vessels (eight are needed for each cryomodule) have been received. The first cryomodule vacuum vessel has been received and is being inspected. Low-level radiofrequency fabrications remain well ahead of schedule. The final shipment of beamline quadrupole magnets has been received. Five more 4-meter beam transport dipole magnets have been shipped from the vendor. All open issues have been closed from the review of the "box" power supplies for the beam transport dipole magnets. Testing of the first article klystron has been delayed until early August.
July 28, 2010
12 GeV tunnel installation tasks during the upcoming Summer 2010 accelerator shutdown include installation of cables in the new zones of the north and south linacs, magnet cable labels, 10 new floor pedestals for Hall D beam line girders, Arc 10 stands, waveguide hangers, low conductivity water (LCW) west arc headers, and extension of the north linac master oscillator. Lessons learned during this shutdown will be used to refine plans for installation work during the six-month shutdown starting in May 2011.
As part of an effort to coordinate the 12 GeV Project needs, the JLab facilities group is developing an on-line database for related space and storage requests including offsite rentals. Coordination of equipment for material handling and transportation continues in order to ensure installation activities are adequately supported to perform the work safely.
July 21, 2010
Civil construction for the 12 GeV Upgrade is now 25 percent complete. The North and South Access Building additions have taken shape, with the structural steel and metal siding installed. At Hall D, the last 10 feet of the walls is being framed with structural steel. A portion of the concrete floor for the tagger area has been placed and the contractor is installing the reinforcing steel for the remaining portion of the concrete floor. The contractor for the Central Helium Liquefier (CHL) utility upgrades has mobilized and the new transformer and switchgear at the South Linac is being installed.
July 14, 2010
The second group of four Barrel Calorimeter (BCAL) modules for the Hall D GlueX spectrometer has arrived at JLab from the University of Regina, Saskatchewan, Canada. The third group of four BCAL modules have been built and sent for final machining in Regina. A successful readiness review for construction of the Hall D Forward Calorimeter was held at Indiana University. A new Cockcroft-Walton type high-voltage synthesizer-and-divider base has been prototyped there for the photomultiplier tubes that read out the 3,000 lead-glass blocks comprising the detector. The two large, precision endplates that support the 28 cylindrical layers of straw tubes of the Hall D Central Drift Chamber have been readied at Carnegie Mellon University, with first shipments of straws arriving this month. Tests of first-article preamps, using the custom ASIC preamp developed in collaboration with the University of Pennsylvania, have been coupled to the Forward Drift Chamber prototype at JLab. Operation of the new 72-channel 125 MHz pipelined flash analog to digital converter has also been tested in this setup with good results. Final manufacturing drawings for the Hall D tagger magnet and coil to be used in the upstream photon production area are being checked.
July 7, 2010
Deliveries of the new beam transport quadrupole magnets near completion, with more than 100 of the 114 ordered now on site. Closure has been reached with the vendor for the beam transport septa on annealing of the iron, and a path forward for the coil insulation for those septa magnets has been identified. During the most recent tests of the first article klystron, the klystron vendor encountered heating issues in the components that receive the power out of the klystron; straightforward corrective modifications are being made and the next test is projected for mid-July. A preliminary design review of the "box" power supplies for the beam transport dipole magnets was held. Installation of the Central Helium Liquefier system hardware continues in the new CHL building addition. The first two 12 GeV production superconducting radiofrequency cavities are expected to be delivered this month.
June 30, 2010
Details are being finalized for 12 GeV tunnel installation tasks scheduled for the Summer 2010 scheduled accelerator shutdown. The tasks are being coordinated with the other planned shutdown activities in order to understand resource constraints and identify possible work location conflicts in the tunnel. The installation contract for the west arc low conductivity water (LCW) header has been awarded and the work will be done in this time period. Efforts continue to coordinate 12 GeV assembly space and storage needs with the JLab facilities management group. Off-site storage and workspace has been obtained to support 12 GeV activities such as some Hall D detector fabrication, and temporary storage for accelerator magnet stands and cryomodule components.
June 23, 2010
Civil construction continues to make progress. On the North and South Access building additions, the transformers have been placed on the concrete pads, and the structural steel is set. Metal siding is being installed at the South Access building addition. At the South Linac service building, the contractor has started the ductbank for the power upgrade. On the Hall D Complex, the contactor has completed the Hall D concrete walls. These walls will be another 10 feet higher with structural steel framing. The contractor is also installing the under-slab grounding grid and plumbing at the Tagger Area.
June 16, 2010
The Super High Momentum Spectrometer (SHMS) is being built for Hall C. It has a total of five superconducting magnets. The contract for the horizontal bend magnet was placed with the National Superconducting Cyclotron Laboratory at Michigan State University, where several similar magnets have been built in the past for that facility. The manufacturing design for the first quadrupole magnet (Q1) is progressing at Scientific Magnetics in Abingdon, Oxfordshire, U.K. The bids for the other two quadrupole magnets (Q2 and Q3), and the bids for the dipole magnet are now under evaluation at JLab. The required superconducting cable for the magnet coils is in hand and will be soldered to an extruded copper stabilizer that was recently ordered. The cryogenic control reservoirs for the magnets are under fabrication at Meyer Tool in Chicago. A contract for the production drawings for the SHMS support structure and shield house was recently placed with AMSEC of Newport News. The bids for the five large power supplies have been evaluated, and the contract will be placed following the contract awards for the remaining magnets.
June 9, 2010
Ninety of the expected 114 new beam transport quadrupole magnets have been delivered; all magnets that have been tested are significantly better than the specifications by a factor of four or more. Preliminary analysis of the field data for the 1st article 4-meter dipole magnet indicates that it is within specifications. Testing of the 1st article klystron has been delayed due to a vacuum leak; testing will resume in June and the vendor projects meeting the contractually scheduled delivery date. Vendor designs for the cathode power supplies and waveguide isolators passed the preliminary review by JLab. Construction of the shunts upgrades has begun. Assembly of the low-level radiofrequency system's stepper motor controller chases has been completed. Installation of the Central Helium Liquefier subsystem hardware has begun in the CHL building addition. Deliveries of the helium circuits and cold vacuum valves for the 12 GeV cryomodules have been completed.
June 2, 2010
Civil construction met its first Level 2 project construction milestone, with the Central Helium Liquefier building addition ready for equipment installation. On the North and South Access building additions, the concrete floor slabs and transformer pads have been placed. Structural steel has been delivered and erection will start this week. On the Hall D Complex, the contractor has completed five of the six sequences for the second lift of the concrete walls. The collimator enclosure concrete roof is placed. Formwork is being installed for the roof of the Hall D truck ramp.
May 26, 2010
Planning for the 12 GeV accelerator and civil installation tasks during the summer accelerator shutdown (Aug. 13) has been revised to align with the new lab schedule. The scheduled accelerator down tentative schedule can be viewed online. Existing planning tools, such as ATLis (Accelerator Task List) and weekly meetings are being used to coordinate 12 GeV installation activities with the accelerator operations group. The 12 GeV installation tasks include the remaining west arc low-conductivity water supply and return lines, Arc 10 stands, four cryomodule baseplates, radiofrequency waveguide hangers and cables. Bi-monthly 12 GeV space planning meetings are being held to coordinate space and storage requirements with Facilities Management and Logistics, which has resulted in the allocation of off-site storage and work space to support 12 GeV assembly activities.
May 19, 2010
The preliminary manufacturing readiness review for the solenoid magnet for CLAS12 was held in May at Wang NMR in California. This included a progress review of the machine preparations for soldering the superconducting cable to the copper stabilizer and for winding the coil. Short sample tests of the superconducting cable for the solenoid are in final stages at the University of Twente, the Netherlands, with good results to date. Production extrusion of the scintillator for the Pre-Shower Calorimeter (PCAL) for CLAS12 is underway at Fermilab. Tests showed that inserting two wavelength-shifting fibers per through-hole into each scintillator slat gave better light yield results than gluing in a single fiber, and this method was adopted for PCAL assembly. A lab for this work is nearing completion at The College of William & Mary. Tests were made of a composite rib structure that would minimize material thickness for the CLAS12 High Threshold Cerenkov Counter (HTCC), and the first eight (of 48) of the 5-inch diameter quartz-face photomultiplier tubes have arrived and are being tested.
May 12, 2010
The sixth (of 37) 4-meter dipole magnet has been received. Deliveries of the new beam transport quadrupole magnets have reached 66; all magnets that have been tested have been significantly better than the specifications. Preliminary testing of the first article klystron by the vendor has begun. Deliveries continue for the cryomodule cold tuners and waveguides; the contract for the warm tuner assemblies has been awarded. The vendor for the iron assemblies to be added to the existing beam transport dipoles has ordered the necessary materials. Critical sub-contracts for the 4.5K coldbox (turbines and absorbers) were placed by the coldbox vendor. A preliminary manufacturer’s engineering review was held at the vendor site for the Central Helium Liquefier warm compressors, and the design was approved. The vendor subsequently placed orders for electric motors, compressors, heat exchangers and coolers.
May 5, 2010
Coordinated planning is well underway for the upcoming summer 2010 scheduled accelerator shutdown, which includes installing the following: the remaining west arc low-conductivity-water (LCW) supply and return lines, Arc 10 stands, four cryomodule baseplates, RF waveguide hangers and cables. Planning for the 12 GeV assembly and installation efforts includes the identification and coordination of requirements for material handling equipment, transportation and storage/assembly space.
At the request of the Office of Nuclear Physics, Daniel Lehman, Director of the Office of Project Assessment in DOE's Office of Science, convened a team of 13 experts in an Independent Project Review of the 12 GeV Upgrade on April 27-28. The purpose of the review was to assess progress in all aspects of the project since last September. The review committee concluded at the closeout that the project is making satisfactory progress and provided ten recommendations to guide activities in the coming months.
April 21, 2010
Civil construction continues to make progress. The construction contractor for the North and South Access Building additions is building forms for the concrete footings. The Central Helium Liquefier building addition is completing the startup and testing of equipment, including the bridge crane. CEBAF Boulevard was re-opened on April 17. A site visit for interested contractors for the CHL utility upgrade was held on April 12, and proposals are due at the end of the month. On the Hall D complex construction site, the contractor continues to excavate for the Tagger Area.
April 14, 2010
The first four of 48 Barrel Calorimeter (BCAL) modules for Hall D have been machined, given final quality assurance checks and readied for shipping to JLab by the team at the University of Regina in Saskatchewan, Canada. The fifth and sixth modules have been built and sent for final machining, and the seventh and eighth are being built. A contract for construction of the Hall D Forward Calorimeter has been awarded to Indiana University. This calorimeter consists of some 3,000 lead-glass blocks that are read out by FEU-84 photomultiplier tubes via new Cockcroft-Walton type high-voltage synthesizer-and-divider bases designed at Indiana University. A contract for fabrication of the Hall D Central Drift Chamber has been awarded to Carnegie Mellon University. This chamber consists of 28 cylindrical layers of straw tubes arranged in groups of radial and axial straws, held between two large precision endplates which were recently received from the vendor and checked at JLab prior to shipment to CMU.
April 7, 2010
The first article four-meter dipole magnet was inspected and accepted at JLab; series production was authorized. Deliveries of beamline quadrupole magnets reached 50 of the total expected number of 125. The contract was awarded for the girders and pedestals to be used for arc 10 and the beamline to Hall D. A vendor site visit was held for the corrector dipole magnets to inspect the first article unit. The contract for the large magnet power supplies was awarded. First article testing of the low-level radiofrequency control boards was successful. First articles of the helium circuit and thermal shield for the cryomodules were received.
March 31, 2010
The construction phase of the 12 GeV Upgrade places demands on shared resources throughout the lab, such as assembly and storage space, as well as shared support services, such as RadCon and survey/alignment. Coordination and integration efforts continue to help lab personnel understand the resource constraints and plan for optimized solutions, including identifying possible efficiencies through purchases of common instrumentation racks and electrical equipment. Coordinated planning is underway for the upcoming summer 2010 scheduled accelerator shutdown, which will include these 12 GeV installation tasks: the remaining west arc low-conductivity water supply and return lines, Arc 10 stands, four cryomodule baseplates, radiofrequency waveguide hangers and cables.
March 24, 2010
Civil construction has made noticeable progress over the last month. On the Central Helium Liquefier Building Addition, metal siding installation is nearly complete. CEBAF Boulevard is planned to re-open during the second week of April. On the Hall D Complex, the first lift of the Hall D concrete walls is complete, bringing them to a height of approximately 15 feet. The second lift will take the concrete walls to a height of approximately 30 feet. On top of the concrete walls will be 10 feet of structural steel frame walls to complete the full height of the walls at 40 feet. In addition to the JLab construction webcam, the Hall D progress can be viewed on the construction contractor's webcam.
March 17, 2010
Detector work is well underway for the focal plane instruments for the Super High Momentum Spectrometer (SHMS) for Hall C, many of which are funded through an NSF-MRI grant. Prototype elements have been tested for the three scintillator hodoscopes at James Madison University and the quartz hodoscope at North Carolina A&T State University. Drift chamber wire tensioning and window materials have been prototyped at Hampton University. Lead glass blocks donated by the Yerevan Physics Institute and NIKHEF have been tested and re-commissioned by collaborators from Yerevan and JLab. Designs for the noble gas Cerenkov counter and the heavy gas Cerenkov counter have been prepared at the University of Virginia and the University of Regina, respectively. The College of William and Mary continues work to integrate the detailed design of the main detector support frame with the shield house. A separate support frame for the lead glass shower counter is part of the shield house itself.
March 10, 2010
Deliveries of materials for the accelerator systems continue. Forty-two beamline quadrupole magnets have been delivered, as well as the first 10 of the cold tuners for the cryomodules. Of particular note is the receipt of the first article 4-meter dipole magnet for arc 10. Site visits and discussions were held with the vendor of the superconducting radiofrequency cavities, and the vendors of the cryomodule end cans and helium vessels. A team also reviewed the 4K coldbox vendor's design package. A review was held of the magnet measurement and mechanical/electrical quality control plan for the beam transport magnets; the reviewers were generally pleased and gave constructive comments. The project received approval from DOE for the contract award package for the warm compressors to be used in the upgraded helium plant.
March 3, 2010
The winter 2010 tunnel work for 12 GeV installation has been completed. Planning efforts for the summer 2010 scheduled accelerator down are in progress. Activities include installation of the remaining west arc low-conductivity water (LCW) supply and return lines, Arc 10 stand installation, the remaining four cryomodule base plates, radiofrequency (RF) waveguide hangers and cable installations. Planning efforts for 12 GeV installation activities during the scheduled six-month accelerator shutdown (May-November 2011) are also in progress.
February 24, 2010
Construction on the solenoid and toroid magnets for CLAS12 in Hall B is proceeding at Wang NMR in California, with system and first manufacturing readiness reviews held in the past two months. Short sample tests of the superconducting cable for the solenoid are underway prior to preparation for winding. The support structure for a first sector of the region 2 drift chamber for CLAS12 has been assembled in the recently refurbished clean room at JLab. The wire stringing using this structure will start later this spring as a joint effort among Old Dominion University, Idaho State University and JLab. Test extrusions of scintillator for the Pre-Shower Calorimeter (PCAL) for CLAS12 recently concluded successfully at Fermilab, with the production extrusion to follow in the next months. Work on components for PCAL, such as photomultiplier tubes, wavelength-shifting fibers and splitters is proceeding apace at James Madison University, Norfolk State University, Ohio University and The College of William & Mary, all supported by a successful collaborative NSF-MRI grant.
February 17, 2010
The first lot of beam transport quadrupole magnets was received. The contracts were awarded for the radiofrequency system's cathode power supplies and for the H-iron that will be used to modify the arc and spreader/recombiner dipole magnets. The first batch of warm-to-cold waveguides for the cryomodules was received. In-tunnel installation activities were completed. In addition, data was acquired on the activation of the magnets; this information will be folded into the work plan for the dipole magnet refurbishment.
February 10, 2010
The January 2010 tunnel work for 12 GeV installation is wrapping up, with tunnel lock-up starting in a few weeks. All radiofrequency waveguides for the penetrations have been installed in the new zones, and final plates and stone filling of the penetrations are in progress. Cryomodule baseplates for the new zones have been installed, with only a few plates remaining for final alignment and grouting. Arc 10 stand layouts and anchor installations have been completed. Installation of the west arc low-conductivity water (LCW) five-inch supply and return line is in progress.
February 3, 2010
Two significant tasks were completed for 12 GeV civil construction. The 5-ton bridge crane was installed in the Central Helium Liquefier building addition. The floor slab for Hall D was placed with approximately 900 cubic yards of concrete (see photos at www.jlab.org). With more than 100 trucks of concrete to place, the operation was done in two, 24-hour sequences. The first sequence started at 2 p.m. on Jan. 26., and the second sequence started at 8 p.m. on Jan. 28. For proper curing of the concrete, the temperature around the slab was monitored around the clock and maintained above 50 F with the use of propane heaters and blankets.
January 20, 2010
The first Barrel Calorimeter (BCAL) module for Hall D is being measured for uniformity and optical properties at the University of Regina, Saskatchewan, Canada. The second module has been stacked and machined to tolerance. The third module is being stacked on a second production table, which enables two modules to be assembled in parallel. Optical tests for the preferred BCAL read-out system, silicon photomultiplier arrays, have successfully concluded using prototypes from one vendor. Further testing, including prototypes from a second vendor, is planned. The Hall D forward drift chamber (FDC) preproduction prototype has been assembled and is undergoing testing in the cosmic ray stand at JLab. A set of 40 preamp cards using a custom ASIC chip designed for the FDC read-out is being procured for extended testing of this detector.
January 13, 2010
Testing of the first article beamline quads was completed and the vendor was approved to proceed with full production. The final step of the superconducting radiofrequency cavity contract was awarded; this phase of the work encompasses the first chemical processing and the rough frequency tuning. The contract for the cryomodule end cans was awarded in December as were the contracts for the rf system's waveguide circulators and the beam transport corrector magnets. Installation work for 12 GeV began during the holiday machine shutdown with replacement of the baseplates for the cryomodule stands and removal of the stones in the penetrations where the rf waveguides for the new cryomodules will be installed.
January 6, 2010
The January 2010 scheduled accelerator shutdown started at the end of December, and tunnel installation work for the 12 GeV Upgrade is in progress. Penetrations have been opened in preparation for the new radiofrequency waveguide installations. Base plate swaps for the new cryomodules are near completion. Electrical power tie-ins to support the civil construction for the Central Helium Liquefier (CHL) building addition and the Hall D Complex have been completed. Additional 12 GeV work planned for this shutdown period include Arc 10 stand layout with anchor installation and the west arc low-conductivity water (LCW) header installations.