[Comparison of five patient-controlled analgesia drug delivery devices]

We report the performance and our impression of five patient-controlled analgesia (PCA) drug delivery devices commercially available; Atom PCA Pump 500, AP-II, Deltec CADD-PCA 5800, Sabratek 6060 and Verifuse. Each of these devices has unique features for PCA. However, these devices still leave some room for improvement. Especially, we hope that future devices will be lighter to carry and use dry batteries more economically. In order to use these devices effectively for the management of pain, it is important to understand their characteristics.

Proposal of a high-field superconducting wiggler for a slow positron source at SPring-8

A low-energy positron beam is a unique probe of materials. In high-energy electron and positron storage rings it is possible to generate intense synchrotron radiation with a photon energy of 1-3 MeV by installing a high-field (8-10 T) superconducting wiggler. High-energy photons are converted to low-energy positrons by using a suitable target-moderator system. For an 8 GeV electron storage ring at a beam current of 100 mA, final yields are estimated to be about 10(8)-10(10) slow-e(+) s(-1) or larger depending on the moderation efficiency, with the size of the positron source 10(1)-10(2) cm(2). In the present work a wiggler magnetic system of 10 T is proposed. The main parameters of the superconducting wiggler are presented.

A method to provide magnet-free long straight sections in low-emittance synchrotron radiation sources

In a low-emittance synchrotron radiation source it is difficult to provide magnet-free long straight sections (MLSSs) a few tens of metres long because introducing MLSSs to the radiation source causes symmetry breaking and markedly reduces dynamic stability. To overcome this difficulty and realize MLSSs in such a ring, a method of building MLSSs is proposed starting from the stable lattice with high symmetry and proceeding via a transient lattice.

Production of intense low-energy positron beams with synchrotron radiation

A low-energy positron beam is a unique probe of Fermi surfaces, defects, surfaces and interfaces. In high-energy electron and positron storage rings (E > 6 GeV) it is possible to generate intense synchrotron radiation with 1-3 MeV photons by installing a high-field superconducting wiggler. The strength of the wiggler should be ~8-12 T. High-energy photons are emitted from the wiggler and converted to low-energy positrons by using a suitable target-moderator system. For an 8 GeV electron storage ring at a beam current of 100 mA, final yields are estimated to be ~10(10)-10(12) (slow-e(+) s(-1)) with the size of positron source ~10(2)-10(3) cm(2). The possibility of increasing the brightness of the low-energy positron beam is discussed. Advantages of using synchrotron radiation for producing positrons are pointed out. The effect of a superconducting wiggler on the stored electron beam is also discussed.