To evaluate the performance of a high current H− rf-driven volume ion source, the Superconducting Super Collider ion source was modified to accommodate a set of cesium dispensers so that a trace amount of cesium could be introduced into the plasma grid collar. A plasma grid heater element controls the temperature of the cesiated surfaces and the rate of cesium dispensation. With this modification, beam currents in excess of 100 mA and electron to H− current ratios close to one have been observed. In contrast, the uncesiated source provided 30 mA of H− beam with an e/H− ratio ≥25. In both cases the source was operated with a 100 μs beam pulse width at a 10 Hz repetition rate, and an extraction voltage of 35 kV. This cesium enhanced source is a strong candidate for use in high current H− accelerators.

The superconducting super collider rf-driven volume ion source routinely provided 35 kV, ≳30 mA H− beams with normalized rms emittances (εn-rms) <0.1 π mm mrad. The source was typically operated with a 100 μs beam pulse width at a 10 Hz repetition rate. To enhance H− output, the ion source was modified to accommodate a set of cesium dispensers so that a trace amount of cesium could be introduced into the plasma grid collar. A plasma grid heater element controls the temperature of the cesiated surfaces and the rate of cesium dispensation. Beam currents in excess of 100 mA and electron to H− current ratios close to one have been observed. Emittance measurements at 70 mA suggest a 20% increase over uncesiated emittance values. Improvements in the beam emittance are fully expected when the extraction optics are optimized. This enhanced, very reliable source is a strong candidate for high current H− accelerators.

The Superconducting Super Collider (SSC) ion source is required to provide a 30 mA H− beam at 35 keV with a normalized rms emittance (εn-rms) of less than 0.18 π mm mrad. An rf-driven volume source was chosen for the commissioning of the SSC linear accelerator (Linac). The divergent ion source output beam is matched into the radio frequency quadrupole accelerator (RFQ) by an electrostatic low-energy beam transport (LEBT). The SSC Linac injector (consisting of ion source, LEBT, and RFQ) is required to provide 25 mA of H− beam (pulse width of 9.6–35 μs at 10 Hz repetition rate) at 2.5 MeV with transverse normalized rms emittance (εt-n-rms) of less than 0.2 π mm mrad and longitudinal normalized rms emittance (εl) of less than 0.82×10−6 eV s. The performance of our rf volume source and initial experimental results from the SSC injector are discussed.

The Superconducting Super Collider (SSC) ion source is required to provide a 35 kV, 30 mA H− beam, with a normalized rms emittance (εn‐rms) of less than 0.18 π mm‐mrad and a pulse width of 7–35 μs at a 10 Hz repetition rate. An RF‐driven volume source is chosen for the initial commissioning of the SSC linear accelerator (LINAC). An extensive experimental program has been under way to characterize the SSC volume ion source. We have achieved εn‐rms as low as 0.06 π mm‐mrad with the RF volume source while meeting all other SSC ion source operating requirements. The available experimental results pertinent to the performance of the SSC RF volume ion source will be discussed.

The SSC LEBT (Low Energy Beam Transport) device focuses and steers a divergent 30 mA H- beam extracted at 35 kV from the volume ion source into a strongly converging beam to match the acceptance of the 2.5 MeV RFQ. Of the LEBT candidates, an einzel lens and HESQ (Helical Electro-Static Quadrupole) are presently under study at the SSC. The experimental emittance results for the einzel lens at the RFQ acceptance plane are compared to AXCEL simulations. A comparison is made between the PARTEQ simulated percent of beam transmitted through the RFQ with the experimentally measured beam and with the simulated AXCEL beam

The Superconducting Super Collider ion source/LEBT produces and focuses a 35 keV 30 mA H- beam into the RFQ. The beam emittance (εn-rms, and its other characteristics, are measured using a slit and collector diagnostic system. The resultant data is analyzed by two separate applications. Both the hardware and software involved are discussed. Result examples are presented

The Superconducting Super Collider (SSC) LINAC Injector consists of an ion source, low energy beam transport (LEBT) and radio frequency quadrupole accelerator (RFQ). The LINAC Injector is required to provide 25 mA of H/sup /eam (pulse width of 9.6-48 /spl mu/s at 10 Hz repetition rate) at 2.5 MeV with transverse normalized rms emittance (/spl epsisub t-n-rms/) of less than 0.2 /spl pi/ mm-mrad and longitudinal normalized rms emittance (/spl epsisub 1/) of less than 0.82*10/sup -6/ eV-s. An RF-driven volume source was chosen for the initial commissioning of the SSC LINAC Injector. The RF volume source generates beams with /spl epsisub t-n-rms/ as low as 0.06 /spl pi/ mm-mrad while meeting all other SSC ion source operating requirements (30 mA at 35 keV). The highly converging input beam required by the SSC RFQ is provided by a dual einzel lens. The initial experimental results from commissioning of the SSC LINAC injector and experimental results pertinent to the performance of the SSC ion source and LEBT are discussed.< >