Pelletron

The 2.5 MeV Pelletron accelerator SIRIUS at the École polytechnique

A Pelletron is a type of electrostatic generator, structurally similar to a Van de Graaff generator.[1] Pelletrons have been built in many sizes, from small units producing voltages up to 500 kilovolts (kV) and beam energies up to 1 megaelectronvolt (MeV) of kinetic energy, to the largest system, which has reached a DC voltage of over 25 megavolts and produced ion beams with energies over 900 MeV.

According to the review paper of F. Hinterberger[2] the pelletron was first developed in the mid 1960s by Prof. Raymond Herb.[3] In 1965 Ray together with J. A. Ferry and T. Pauly founded the National Electrostatics Corporation, to manufacture pelletrons as a solution to the problems of ever larger Van de Graaff machines required at that time for particle physic research.

As in the Van de Graaff machine, electric charge is moved by a mechanical transportation system. The charge is carried on a chain of 'pellets' (conductive tubes connected by links made of insulating material), that is used to build up high voltages on the Pelletron terminal. The moving pellets form variable capacitances on which charge is trapped, so as the pellet moves from the charging electrode towards the accumulator and the capacitance to ground reduces, the voltage rises, as charge cannot enter or leave the pellet except at the electrodes.

  1. ^ Hellborg, R. (2019). The electrostatic accelerator: a versatile tool. San Rafael, California. ISBN 9781643273563.{{cite book}}: CS1 maint: location missing publisher (link)
  2. ^ F. Hinterberger (2006). "Electrostatic accelerators". CAS - CERN Accelerator School: Small Accelerators. doi:10.5170/CERN-2006-012.95.
  3. ^ Henry H. Barschall (1997). Raymond Herb. Biographical Memoir. Washington DC: National Academy of Sciences. doi:10.17226/5859. ISBN 978-0-309-05788-2. Retrieved November 17, 2022.