[en] Coupling mechanism (11) for engaging and lifting a load (12) has a housing (19) with a guide passage (18) for receiving a knob (13) which is secured to the load (12) through a neck (15) of smaller diameter. A hollow ball (23) in the housing (19) has an opening (27) which receives the knob (13) and the ball (23) is then turned to displace the opening (27) from the housing passage (18) and to cause the neck (15) to enter a slot (29) in the ball (23) thereby securing the load (12) to the coupling mechanism (11) as elements (49) of the housing (19) block travel of the neck (15) back into the opening (27) when the ball (23) is turned to the load holding orientation. As engagement of the load (12) and locking of the coupling mechanism are accomplished simultaneously by the same ball (23) motion, operation is simplified and reliability is greatly increased. The ball (23) is preferably turned by a motor (32) through worm gearing (36) and the coupling mechanism (11) may be controlled from a remote location. Among other uses, the coupling mechanism (11) is adaptable to the handling of spent nuclear reactor fuel elements (12)

[en] This paper describes the normal conducting linac design that is part of the Accelerator for Production of Tritium (APT) project. The new version of PARMILA designed this linac. This linac accepts the beam from the 6.7 MeV radio frequency quadrupole without a separate matching section. At about 10 MeV, it has a smooth transition in the length of period from 8βλ to 9βλ in quadrupole focusing lattice. This adjustment of the period was needed to provide sufficient space for the quadrupole focusing magnets and beam diagnostic equipment. The linac consists of the coupled cavity drift tube linac up to 97 MeV and coupled cavity linac above 97 MeV

[en] This paper describes an rf structure with high shunt impedance and good field stability for particle velocities o.1 ≤ β ≤ 0.5. Traditionally, the drift-tube linac (DTL) has been the structure of choice for this velocity range. The new structure, called a coupled-cavity drift-tube linac (CCDTL), combines features of the Alvarez DTL and the π-mode coupled-cavity linac (CCL). Each accelerating cavity is a two-cell, 0-mode DTL. The center-to-center distance between gaps is γλ. Adjacent accelerating cavities have oppositely directed electric fields, alternating in phase by 180 degrees. The chain of cavities operates in a π/2 structure mode so the coupling cavities are nominally unexcited. We will discuss 2-D and 3-D electromagnetic code calculations, and some initial measurements on a low-power model of a CCDTL. We will compare shunt impedance calculations for DTL, CCL, and CCDTL structures. The CCDTL has potential application for a wide range of ion linacs. For example, high-intensity proton linacs could use the CCDTL instead of a DTL up to an energy of about 200 MeV. Another example is a stand-alone, low-duty, low-current, very high gradient, proton, cancer therapy machine. The advantage for this application would be a saving in the cost of the machine because the linac would be short

[en] An ODMR study of YAlO³ has been made at 1.6 deg K using an X-ray induced luminescence band, peaking at 223 nm. The ODMR spectrum is unusual, showing the full symmetry of the crystal and also a weak exchange interaction between the recombining carriers. This behaviour is intermediate between that found for recombination of donor-acceptor pairs in semiconductors and for self-trapped excitons in strongly ionic solids. An intense luminescence band of Y²O³ at 364 nm does not show ODMR. Weak, sample-dependent luminescence of EuAlO³ and LaAlO³ in the near ultraviolet has also been studied but, again, does not show ODMR. (author)

[en] An ODMR study of YAlO³ has been made at 1.6 K using an x-ray-induced luminescence band, peaking at 223 nm. The ODMR spectrum is unusual, showing the full symmetry of the crystal and also a weak exchange interaction between the recombining carriers. This behaviour is intermediate between that found for recombination of donor-acceptor pairs in semiconductors and for self-trapped excitons in strongly ionic solids. An intense luminescence band of Y²O³ at 364 nm does not show ODMR. Weak, sample-dependent luminescence of EuAlO³ and LaAlO³ in the near ultraviolet has also been studied but, again, does not show ODMR. (author)

[en] Trigonal sites of Yb³⁺ in CeO₂ and ThO₂, where an F^- ion substitutes for an O^2- ligand, have been characterised by ¹⁹F ENDOR. Transferred hyperfine interaction (THFI) parameters have been measured for the ¹⁹F ligand, and also in CeO₂ for the ¹⁷O ligand on the C₃ axis. A model which accounts for the magnitude and anisotropy of these interactions has been constructed based upon a molecular orbital theory: this requires large contributions to the THFI parameters from the electrostatic polarisation of both the ligand and the paramagnetic ion. (author)

[en] We are applying the new coupled-cavity drift-tube linac (CCDTL) to a conceptual design of a high-current, CW accelerator for transmutation applications. A 350-MHz RFQ followed by 700--MHz structures accelerates a 100-mA proton beam to I GeV. Several advantages stem from four key features: (1) a uniform focusing lattice from the start of the CCDTL at about 7 MeV to the end of the linac, (2) external location and separate mechanical support of the electromagnetic quadrupole magnets, (3) very flexible modular physics design and mechanical implementation, and (4) compact, high-frequency structures. These features help to reduce beam loss and, hence, also reduce potential radioactivation of the structure. They result in easy alignment, fast serviceability, and high beam availability. Beam funneling, if necessary, is possible at any energy after the RFQ

[en] Recent developments in W-band (-100 GHz) traveling wave tube technology at Los Alarnos may lead to a compact high-power W-band RE source. A conceptual design of a compact 8-MeV electron linac that codd be powered by this source is presented, including electromagnetic structure calculations, proposed rnicrojbbrication and manufacturing methods, supporting calculations to estimate accelerator performance, and gumma production rates based on preliminary target geometries and expected output beam current.

[en] The Coupled-Cavity Drift Tube Linac (CCDTL) is a relatively new RF accelerator structure which plays a major role in the APT Low-Energy Linac (LEL) design. Engineering development is pushing ahead on several fronts, including thermal management, fabrication procedures, cavity and coupling slot tuning, high-power prototype fabrication and testing, supports and alignment, vacuum, and provisions for beam diagnostics. Fabrication of the CCDTL Low-Beta Hot Model is nearly complete, and high-power RF tests will commence soon. In 1999, the authors will begin the fabrication of 11 meters of CCDTL to be added to the Low-Energy Demonstration Accelerator. In 2001, it will take the 100 mA beam from 6.7 MeV to 10.05 MeV, producing the world's most powerful proton beam. The authors are also starting the design of a CCDTL 96 MeV Hot Model to demonstrate cooling of an intermediate-Beta version of the structure. The 14cm-long, 9cm diameter drift tube has roughly 5kW dissipated on it. This all leads to the final mechanical design of the 113m long CCDTL for the APT plant linac

[en] Conventional designs for proton linacs use a radiofrequency quadrupole (RFQ), followed by a drift-tube linac (DTL). For higher final beam energies, a coupled cavity linac (CCL) follows the DTL. A new structure, the coupled-cavity drift-tube linac (CCDTL) combines features of an Alvarez DTL and the CCL. Operating in a π/2 structure mode, the CCDTL replaces the DTL and part of the CCL for particle velocities in the range 0.1 < β < 0.5. The authors present a design concept for a compact linac using only an RFQ and a CCDTL. This machine delivers a few mA of average beam current at a nominal energy of 70 MeV and is well suited for radioisotope production