Secondary emission electron gun using external primaries

Patent · Tue Jun 05 00:00:00 EDT 2007

OSTI ID:909577

Srinivasan-Rao, Triveni ^[1]; Ben-Zvi, Ilan ^[2]; Kewisch, Jorg ^[3]; Chang, Xiangyun ^[4]

---

1. Shoreham, NY
2. Setauket, NY
3. Wading River, NY
4. Middle Island, NY

An electron gun for generating an electron beam is provided, which includes a secondary emitter. The secondary emitter includes a non-contaminating negative-electron-affinity (NEA) material and emitting surface. The gun includes an accelerating region which accelerates the secondaries from the emitting surface. The secondaries are emitted in response to a primary beam generated external to the accelerating region. The accelerating region may include a superconducting radio frequency (RF) cavity, and the gun may be operated in a continuous wave (CW) mode. The secondary emitter includes hydrogenated diamond. A uniform electrically conductive layer is superposed on the emitter to replenish the extracted current, preventing charging of the emitter. An encapsulated secondary emission enhanced cathode device, useful in a superconducting RF cavity, includes a housing for maintaining vacuum, a cathode, e.g., a photocathode, and the non-contaminating NEA secondary emitter with the uniform electrically conductive layer superposed thereon.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-98CH10886
• Assignee: Brookhaven Science Associates, LLC (Upton, NY)
• Patent Number(s): 7,227,297
• Application Number: 10/917,309
• OSTI ID: 909577
• Country of Publication: United States
• Language: English

Related Subjects

47 OTHER INSTRUMENTATION