SOW_PPSS.pdf

Special Notice #: N00173-16-R-DD01 Attachment 1

Statement of Work (SOW)

Pre-Pulse Suppression Switches

Background The Naval Research Laboratory (NRL) is the corporate research laboratory for the Navy and Marine Corps. NRL’s Pulsed Power Physics Branch (Code 6770) of the Plasma Physics Division of the Naval Research Laboratory performs the research necessary to advance existing pulsed power driven applications and to develop and promote new pulsed-power architectures and applications. Historically these applications have included the following:

(a) Nuclear weapons effects simulation

(b) High-brightness flash x-ray radiographic sources

(c) Electromagnetic projectile launcher technologies

(d) High-energy density laboratory plasmas

(e) Active detection of special nuclear materials

(f) The development of new pulsed power-driven applications and enabling technologies

The Pulsed Power Physics Branch is involved in the research, design, development, integration, and testing of pulsed-power-driven radiation sources and pulsed-power architectures for tactical and environmental characterization. Pulsed Power Branch advance the research the areas listed above.

Objectives

The NRL’s Pulsed Power Physics Branch proposes to purchase Pre-Pulse Suppression Switches for Mercury, a unique terawatt-class pulsed-power generator, to enhance our high-power diode capability in the 2.3 MV positive polarity operating mode. This mode is used to generate high power electron and ion beams that produce intense radiation pulses. The present diode research programs with Mercury are significantly impaired by the lack of these critical components, resulting in over 40 kV of pre-pulse in this critical operating mode that severely degrades diode and radiation pulse performance. The lack of these switches also prevents critical beam current diagnostics. Additionally, the present connections between the pulse-forming lines (PFLs) and induction cells require draining approximately 4000 gallons of water and 26,000 gallons of oil to clean the cell insulators, which imposes a significant maintenance burden and limits machine availability. This purchase would provide us with a pre-pulse suppression switches closest to the diode, reducing the pre-pulse by a significant factor, and thereby dramatically improving our ability to field and diagnose high-power diodes for radiography and ion beam production. Acquisition of this pre-pulse suppression system would also provide a substantial reduction in maintenance time and associated costs. These high-power diodes produce debris that is blown backward into the acceleration cells, which must be periodically cleaned from the cells closest to the diode to prevent severe damage to the accelerator. These switches would remove the need to drain the water and oil systems for cell cleanings in this operating mode by serving as disconnection joints between the PFLs and induction cells that would withstand the fluid pressure. The maintenance time reduction would extend to all experiments that use this operating mode, projected to be approximately 2/3 of facility usage, including both NRL and external users at the Mercury facility.

The pre-pulse suppression switch design would be based on the Fast Pulse Gamma generator.

Using gas fill instead of oil fill (previous generation) will provide additional pre-pulse minimization and reduce the maintenance burden compared with traditional oil-filled pre-pulse-suppression switches. The NRL’s Pulsed Power Physics Branch estimates that the new switches will reduce our work load by approximately 360 person-hours per year, including installation, testing, cell cleaning, and pulsed power analysis.

Scope

In support of this research program, the contractor shall develop and deliver two (2) pre-pulse suppression switches for the Mercury pulsed power generator. The contractor's engineers shall work closely with NRL experimental researchers to test this hardware.

Work Requirements The contractor shall design, procure, build, and test two (2) pre-pulse suppression switches for the Mercury pulsed power generator, consistent with the existing design and mated to the current hardware. Modifications to existing pulse forming line (PFL) hardware may be required;

a low-impact solution is desired. Specifications require that the pre-pulse switches (PPS) must:

• Mate to existing PFL hardware while maintaining the relative positioning of the Marx tank and output adder cells, i.e. the overall PFLs are the same length.

• Modifications, if any, to the existing PFL must be reversible, allowing NRL to quickly revert to original configuration,

• Hold-off a minimum of 1.3 million Volts (1.3 MV) for duration of 50 nanosecond (ns) pulse,

• Conduct minimum of 150 thousand Amps (150 kA),

• Hold off a minimum of 30 thousand Volts (30 kV) across axial gap,

• Maximum inductance of 50 nanohenries (nH),

• Reduce the prepulse downstream of any individual switch to less than current 1.5% level

• Use SF6 gas as the switching medium,

• Allow minimum full-power 20 shots without requiring disassembly and/or cleaning.

The contractor shall test the hardware on the Mercury pulsed power generator at NRL upon delivery. It is assumed that the pre-pulse switches will be installed by NRL with the participation on site by the contractor. Testing will be performed in accordance with a test plan developed by the contractor and NRL. It is assumed that Mercury is operated by NRL with participation on site by the contractor. The contractor will summarize the switch performance in a test report.

Delivery

The contractor shall deliver two (2) pre-pulse suppression switches for the Mercury pulsed power generator consistent with the existing design and easily mated to the current hardware.

The contractor shall deliver all hardware drawings generated under this contract in electronic form. Delivery should be to the Naval Research Laboratory, Bldg. 256: Room 156, 4555 Overlook Avenue SW, Washington, DC 20375.

POC: Dr. Ray Allen (202) 404-5324

Government Furnished Equipment

If existing hardware needs to be measured and modified to allow for attachment of the new PPS, NRL will provide the necessary hardware if deemed outside the scope of this contract.

These will be considered GFE as they are critical to the completion of the work. Testing time at NRL will also be provided, which includes personnel, use of data acquisition equipment, and rigging gear.

Security

All Contractor personnel who require NRL base access or access to NRL unclassified material and/or unclassified systems shall possess a favorably completed DoD National Agency Check with Law and Credit (NACLC). No classified material will be accessed, handled, or generated in regard to work on this contract. Contractor personnel will not have user access to NRL information systems for performance of this contract.

Travel

The contractor will need send their staff to NRL for testing of the new PPS on the Mercury pulsed power machine. Estimated time at NRL is less than 3 weeks.

Special Material Requirements

None

Other Unique Requirements

None.

Place of Performance

Work will be completed both at the Contractor’s facility (design, fabrication, initial testing if any) and at the Government facility (testing). The contractor may use subcontractors for completion of the work. NRL personnel will remove and disassemble the PFLs prior to modification, as well as reassemble and reinstall afterward. The contractor will be on-site for installation and testing at NRL.

Period of Performance

The period of performance will be one year after the award of the contract. It is estimated that 3 months design, 6 months fabrication and assembly, and 3 months testing will be required.

Scheduling of the fabrication using GFE will need to be coordinated with NRL staff as it impacts our operations.