The Applied Vacuum Division of Anderson Dahlen Delivers Multiple, Fully-Processed Chambers to National Energetics in Support of 10PW Laser System

Posted on: February 8, 2018

Phase 1 – Vacuum Chambers (VC1 and VC2)

National Energetics, Inc. (www.nationalenergetics.com) was founded in 2010 to leverage emerging laser technologies into next-generation ultra-intense laser systems. The Austin-based company designs and manufactures custom high power, Chirped Pulse Amplifier (CPA) lasers and Disc Amplifiers for research applications ranging from Terawatts (1012W) to Petawatts (1015W). As a result of continued innovation, National Energetics has developed high power laser systems that can produce a “shot” at a rate of 1/min while other lasers need 20-60 minutes for the optics to recover. To date, National Energetics is one of only a handful of companies in the world to demonstrate the production and long-term use of a Petawatt laser.

In early 2016, Anderson Dahlen’s Applied Vacuum Division was approached to provide a proposal to manufacture two large box chambers for a 10PW laser system. The vacuum chambers were designated as VC1 (13.7’L x 3.3’W x 2.3’H) and VC2 (15.4’L x 4.3’W x 3.6’H) with 304L SS construction for the chamber body and AL 5083 for the doors. The scope of the build also included carbon steel frames, internal aluminum optical tables, and (16) edge-welded bellows, optical decoupling assemblies for vibration isolation. The chambers were required to operate at a base pressure of 1 x 10-6 Torr with a leak rate of < 1x10-8 std-cc/sec of Helium or better.

The Applied Vacuum Division of Anderson Dahlen was awarded the contract in June 2016 and Phase 1 of the chamber portion of the build began. The VC1 and VC2 chambers contain highly sensitive optical grade mirrors. During a “shot”, the remaining atmosphere in the vacuum becomes excited by the laser’s high energy, and the presence of hydrocarbons can result in irreparable damage to $M’s of optics. Therefore, the chambers and internal optical tables were required to be thoroughly cleaned and baked for oil-free, high-vacuum service. Over a 6 month build schedule, ADI’s Project Managers and Design Engineers worked closely with National Energetics’ team to develop and finalize the manufacturing drawings and final test/checkout procedures.

After the completion of manufacturing, the chambers were thoroughly cleaned, baked, and inspected with a residual gas analyzer (RGA). The sum of the partial pressures for masses 45 amu and above were required to be below 1×10-10 Torr with a water peak no greater than 1×10-8 Torr. In February of 2017, the completed chamber assemblies were delivered to National Energetics to be incorporated into their cleanroom test setup.

Phase 2 – Spatial Filter Chambers (SF1 and SF2)

During and after the install of VC1 and VC2, The Applied Vacuum Division of Anderson Dahlen received contracts for the Spatial Filter 1 (SF1) and Spatial Filter 2 (SF2) Chamber Assemblies. VC1/2 and SF1/2 comprise the majority of the vacuum chamber requirements for the amplifier section of the 10PW Laser System. In the amplifier section, the laser pulse must be stretched for signal conditioning and then compressed in a later stage prior to reaching the target. The spatial filters are long (SF1 – 17.5’, SF2 – 36.3’), telescoping chamber assemblies that aid in stretching the laser beam, and the sections increase in diameter in order to accommodate the beam divergence.

Like VC1 and VC2, the Spatial Filter Chambers were required to operate at the same base pressures and meet the same RGA scan requirements. SF1 was delivered in March of 2017 with SF2 following in November. With all chambers now delivered, National Energetics is proceeding towards the next milestone with the 10PW laser system to be delivered to their customer in 2018.

The Applied Vacuum Division of Anderson Dahlen supports projects of all sizes across a variety of markets including Vacuum, Chemical, Bio-Pharmaceutical, Food & Beverage, and Nuclear. With the conclusion of our latest expansion, Anderson Dahlen has ~250,000 ft2 of manufacturing space across 2 facilities in the Twin Cities area of Minnesota. Our current manufacturing envelope is 20’ in a single length and 14’ in diameter – larger projects possible. Furthermore, we have added 5,000+ ft2 of HEPA filtered clean space for large project assembly, a class 10,000 cleanroom, RGA scan, and configurable bakeout capabilities up to 250C. Our current team of 220 employees includes 50 welders, 20 CAD Design/Engineering Staff, 5 PMP® Certified Project Managers, and 5 AWS Certified Weld Inspectors. Lastly, Anderson Dahlen can manufacture PED marked and ASME U, R, M, and PP stamped vessels <3,000 psi.