33. RADIO FREQUENCY ACCELERATOR TECHNOLOGY Maximum Phase I Award Amount: $200,000 Maximum Phase II Award Amount: $1,100,000 Accepting SBIR Phase I Applications: YES Accepting STTR Phase I Applications: YES Radio frequency (RF) technology is a key technology common to all high energy accelerators. RF sources with improved efficiency and accelerating structures with increased accelerating gradient are important for keeping the cost down for future machines. DOE-HEP seeks advances directly relevant to HEP applications, and also new concepts and capabilities that further scientific and commercial needs beyond HEP's discovery science mission. In many cases the technology sought is closely tied to a specific machine concept which sets the specifications (and tolerances) for the technology. Applicants are strongly encouraged to review the references provided. Applications to subtopics specifically associated with a machine concept that do not closely adhere to the specifications of the machine will be considered non- responsive. For subtopics that are not machine-specific, applicants are strongly advised to understand the state-of- the-art and to clearly describe in the application what quantitative advances in the technology will result. a. Low Cost Radio Frequency Power Sources for Accelerator Application Low cost, highly efficient RF power sources are needed to power accelerators. Achieving power efficiencies of 70% or better, decreasing costs below $2/peak-Watt for short-pulse sources, and below $3/average- Watt for CW sources are essential. Sources must phase lock stably (<1 degree RMS phase noise) to an external reference, and have excellent output power stability (<1% RMS output power variation). Device lifetime must exceed 10,000 operating hours. Priority will be given to applications that develop RF power sources operating at frequencies that are in widespread use at the large Office of Science accelerators. Sources may be either vacuum tube or solid state, however: (1) if the proposed source is a vacuum tube, priority will be given to applications for tubes with operating voltages <100kV, and (2) if the proposed source is a solid-state power amplifier, strong evidence and arguments must be presented as to how the R&D will enable the cost metric above to be met. For normal conducting accelerators, microsecond-pulsed high-peak-power sources are needed that operate at L-band or higher frequencies. The peak output power of individual sources is flexible but must be compatible with delivering ~100 MW/meter to compact accelerators. The source must support >0.1% duty factor operation. For superconducting accelerators, both millisecond-pulsed and CW sources are needed that operate at L- band frequencies. The peak output power of individual sources is flexible but must be compatible with delivering ~100 kW/meter to high power accelerators. If the source is not CW capable, it must support >5.0% duty factor operation. Applications must clearly articulate how the proposed technology will meet all metrics listed in this section. Questions Contact: Eric Colby, Eric.Colby@science.doe.gov b. Automation of SRF Cavity String Assembly SRF cavities and other metallic components are assembled together in a cleanroom environment. At present the largest impact on the quality of the assembly is the human factor. In order to minimize this impact and also to decrease touch labor and cost, robot-assisted assembly technology is of great interest. Full digitalization of the assembly area, contactless measurement of the component positions, assisted positioning and alignment are some of the steps that could be implemented. The ultimate goal of the proposal submitted is to develop a contactless technology to reconstruct the pose of high-reflecting metallic components to enable robot assisted assembly of SRF components in a cleanroom environment. Questions Contact: Ken Marken, ken.marken@science.doe.gov c. Advanced Conduction Cooling for SRF Systems The implementation of cryocoolers to reach the operating temperature of both SRF and SC magnet devices is very appealing for compact accelerators as well as stand-alone experimental and medical applications. There are clear opportunities for technology advances that might improve such systems for these applications. Grant applications are sought for (1) coupling of the two stages of a cryocooler during the cooldown phase of the device to reduce the time required to reach operating temperature; (2) swapping of a cryocooler (for maintenance or failure) without breaking insulation vacuum and while keeping the system cold; (3) implementing 4 K and 50 K heat pipes to reduce gradients between cold head and device; (4) using hybrid graphene/copper thermal straps to reduce cooldown time. Questions Contact: Ken Marken, ken.marken@science.doe.gov d. Other In addition to the specific subtopics listed above, the Department invites grant applications in other areas that fall within the scope of the topic description above. Questions Contact: Ken Marken, ken.marken@science.doe.gov References: 1. Hartill, D. Accelerating Discovery: A Strategic Plan for Accelerator R&D in the U.S. U.S. Department of Energy Office of Science, April 2015, https://science.osti.gov/-/media/hep/hepap/pdf/Reports/Accelerator_RD_Subpanel_Report.pdf (see especially section 7). 2. Blazey, G. Radiofrequency Accelerator R&D Strategy Report. DOE HEP General Accelerator R&D RF Research Roadmap Workshop, March 8-9, 2017, https://science.osti.gov/-/media/hep/pdf/Reports/DOE_HEP_GARD_RF_Research_Roadmap_Report.pdf (see especially section 5). 3. Henderson, S., Waite, T. Workshop on Energy and Environmental Applications of Accelerators. U.S. Department of Energy Office of Science, see especially section 2.11, 2015, http://science.osti.gov/~/media/hep/pdf/accelerator-rd- stewardship/Energy_Environment_Report_Final.pdf . 4. Zorzetti, S. Computer Vision solutions for Robot-assisted technology in SRF assembly at Fermilab. CERN, February 4-7, 2020, https://indico.cern.ch/event/817780/contributions/3716530/ 5. Wang, M., et al. Development of a Cryogenic Thermal Switch. Cryocoolers 14, Boulder CO, 2004, https://minds.wisconsin.edu/bitstream/handle/1793/21686/76.pdf?sequence=1 6. Park, I., et al. Development of a passive heat switch for fast cooldown by two stage cryocooler. Cryocoolers 18, Boulder, CO, 2014, https://cryocoolerorg.wildapricot.org/resources/Documents/C18/072.pdf 7. Green, M. Connecting Coolers to Superconducting Magnets with a Thermal-Siphon Cooling Loop. Cryocoolers 19, Boulder CO, 2016, https://cryocoolerorg.wildapricot.org/resources/Documents/C19/537.pdf 8. Trollier, T., et al. Flexible Thermal Link Assembly Solutions for Space Applications. Cryocoolers 19, Boulder CO, 2016, https://cryocooler.org/resources/Documents/C19/595.pdf 9. Shu, Q.S., Demko, J.A., et al. Heat Switch Technology for Cryogenic Thermal Management. IOP Conf. Ser.: Mater. Sci. Eng. 278 012133, 2017, https://iopscience.iop.org/article/10.1088/1757-899X/278/1/012133 10. Moehler O., et al. The Portable Ice Nucleation Experiment PINE: A New Online Instrument For Laboratory Studies and Automated Long-term Field Observations of Ice-nucleating Particles. Atmos. Meas. Tech. Discuss, 2020, https://doi.org/10.5194/amt-2020-307
