A drift-tube linac incorporating a ramped accelerating field

A short, high-power linac structure has been designed and is being built; it incorporates a ramped accelerating field for matching a radio-frequency quadrupole (RFQ) to a high-gradient drift-tube linac (DTL). The tank is made of aluminum and can operate at high duty factor. The drift tubes are copper and use new neodymium-iron-boron quadrupoles. The linac is tuned using conical-sweep post couplers and is driven by multiple rf loops. Rapid acceleration of the beam occurs from low to high gradients in a short, compact, and lightweight structure. Because this linac will also be used to test open drift tubes, test results are included on vacuum measurements of high-grade epoxies and plastics that might be used in a drift-tube body