Externally Heated Hollow Cathode Arc Plasma Source for Experiments in Plasma Wakefield Acceleration
oleh: Ryan Roussel, Gerard Andonian, Claire Hansel, Gerard Lawler, Walter Lynn, Nathan Majernik, River Robles, Kunal Sanwalka, Eric Wisniewski, James Rosenzweig
| Format: | Article |
|---|---|
| Diterbitkan: | MDPI AG 2019-09-01 |
Deskripsi
An externally heated, hollow cathode arc source was recommissioned at UCLA for use in experiments to drive plasma wakefields with shaped beams at the Argonne Wakefield Accelerator. The hollow cathode arc source provides a robust plasma column with a density in the <inline-formula> <math display="inline"> <semantics> <msup> <mn>10</mn> <mn>13</mn> </msup> </semantics> </math> </inline-formula>−<inline-formula> <math display="inline"> <semantics> <msup> <mn>10</mn> <mn>14</mn> </msup> </semantics> </math> </inline-formula> cm<inline-formula> <math display="inline"> <semantics> <msup> <mrow></mrow> <mrow> <mo>−</mo> <mn>3</mn> </mrow> </msup> </semantics> </math> </inline-formula> range while external heating of the cathode allows the plasma arc regime to be accessed with applied voltages down to 20 V. Overall source operating principals are described, along with time-resolved plasma current measurements and plasma density characterization with the use of a triple Langumir probe. The results show that relevant plasma densities that match facility beam parameters are readily achievable.