JACoW is a publisher in Geneva, Switzerland that publishes the proceedings of accelerator conferences held around the world by an international collaboration of editors.
TY - CONF AU - Barkley, W.C. AU - Bingham, D.A. AU - Borden, M.J. AU - Burkhart, J.A. AU - Evans, D.J. AU - Lyles, J.T.M. AU - Montross, J.P. AU - O’Hara, J.F. AU - Roller, B.J. AU - Sanchez Barrueta, M. ED - Biedron, Sandra ED - Simakov, Evgenya ED - Milton, Stephen ED - Anisimov, Petr M. ED - Schaa, Volker R.W. TI - Diagnoses and Repair of a Crack in the Drift Tube LINAC Accelerating Structure at LANSCE J2 - Proc. of NAPAC2022, Albuquerque, NM, USA, 07-12 August 2022 CY - Albuquerque, NM, USA T2 - International Particle Accelerator Conference T3 - 5 LA - english AB - Many were perplexed at the inability of Module 3 at LANSCE to operate at peak power and duty factor while running production beam. During the 2018 production run, the DTL began to intermittently break down, leading to a series of root cause investigations. These analyses included eliminating the usual suspects: vacuum leak, debris in tank, driveline window, power coupler, etc. The throttling back of repetition rate from 120 to 60 Hz allowed continued production with a diminished beam, one that reduced neutron flux to three experimental areas. During the annual shutdown in 2019, a more thorough investigation involving the use of x-ray detection, high-resolution cameras and IR detection through site glass windows was performed. After a tenacious search, a 30 cm long crack was discovered in a weld at one of the ion pump port grates. Inaccessibility for welding from the outside and in a confined space, non-intrusive repairs were tried first but were unsuccessful. Ultimately, an expert welder entered the tank to weld the crack under unfamiliar welding conditions. This paper describes the diagnoses, non-intrusive solutions and ultimate repair of the crack in the accelerating structure. PB - JACoW Publishing CP - Geneva, Switzerland SP - 19 EP - 21 KW - vacuum KW - experiment KW - detector KW - linac KW - drift-tube-linac DA - 2022/10 PY - 2022 SN - 2673-7000 SN - 978-3-95450-232-5 DO - doi:10.18429/JACoW-NAPAC2022-MOYE4 UR - https://jacow.org/napac2022/papers/moye4.pdf ER -