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Laboratory Benchtop Accelerator for Charged Particle Detector Calibration


TECHNOLOGY AREA(S): Space Platforms 

OBJECTIVE: Develop a laboratory benchtop-sized charged particle accelerator suitable for supporting calibrations and characterizations of Energetic Charged Particle (ECP) sensors without resorting to licensed radioactive sources and/or large accelerator facilities. 

DESCRIPTION: The Air Force has mandated Energetic Charged Particle (ECP) sensors on all future Air Force satellites. In order for these sensors to accurately measure the space environment, calibration is usually required. For charged particle detector calibrations, the current norm is to use a limited number of accelerator facilities that are large, expensive, and heavily subscribed. Additionally, many facilities are sufficiently old that they may have unexpected down time for maintenance. In addition, the facilities are largely optimized for either medical or radiation effects testing. The typical alternative is to use licensed radioactive sources, which can emit particles at high enough energies to simulate the space environment. However, these radioactive sources emit a spectrum of energies, making true calibration challenging. In addition, radioisotopes that emit high energy protons do not exist. A benchtop- or rackmount-sized, spectrally pure charged particle accelerator as a calibration source would allow for ECP vendors to perform their own calibrations of sensors without licensed radioactive sources and the need for expensive and hard-to-schedule beam time at larger accelerator facilities. The objective of this topic is to develop a laboratory benchtop calibration source that can provide a narrow, spectrally-pure, beam for calibration of ECP sensors. These sources would accelerate electrons from 10 (far term goal) to 50 (near term goal) keV at the lowest energies up to 2 (near term goal) to 5 (far term goal) MeV at the highest energies and/or protons (highly desired) from 1 MeV up to 10 (near term goal) to 100 (far term goal) MeV with a beam energy full width half max of less than 25% (near term goal) or 10% (far term goal). It is desired that the accelerator can be tuned over a range of energies up to its maximum. Unlike much of the current focus in tabletop accelerator research, the desired particle flux needs to be relatively low and ideally adjustable: 1 particle/cm^2/s to 10^6 particles/cm^2/s. It is desired that this low particle flux is ideally retained throughout the entire accelerator so that radiation protection requirements can be kept to a minimum. Methods of limiting the maximum produced particle flux are also highly desired to prevent damage to equipment under test as well as reducing radiation protection requirements. The particle flux produced needs to be as close as possible to an unbunched, continuous source as most existing space particle sensors experience pile-up/dead-time when inter-particle arrival times at the sensor approach 1 µs. Finally, the source beam is desired to be as uniform as possible across at least a 1” beam spot. (SSA TN 952) 

PHASE I: Initial design and modeling of system performance. Perform risk-reduction prototyping of key components leading to demonstration of accelerator behavior. 

PHASE II: Prototype bench accelerator capable of demonstrating all key technologies and identifying necessary additional technology improvements required to meet goals. Demonstrate beam energy tuning capability and document system operation. 

PHASE III: Develop and document final product suitable for straightforward laboratory use and further commercialization. 


1. R. J. England, et al., “Dielectric laser accelerators”, Rev. Mod. Phys., vol. 86, pp. 1337–1389 (2014).; 2. Esarey, E. Schroeder, C. B. & Leemans, W. P. Physics of laser-driven plasma-based electron accelerators. Rev. Mod. Phys. 81, 1229–1285 (2009).; 3. Seidl, P.A. et al. Demonstration of a compact linear accelerator. arXiv:1802.00173 [physics.acc-ph] 1 Feb 2018.; 4. V. Smirnov, S. Vorozhtsov, and J. Vincent, “Design Study of an Ultra-Compact Superconducting Cyclotron”, Nucl. Instr. Meth. vol. 763, pp. 6–12, 2014.

KEYWORDS: Calibration, Accelerator, Charged Particle, Miniaturization 

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