632 research outputs found
Exact Phase Advances for a Two-Stage Collimation System
We propose a specification for a two-stage collimation insertion. We compute exact correlated phase advances between primary and secondary collimators, and determine the number of jaws needed to reach an almost ultimate performance
Optics of a two-stage collimation system
We derive the exact specification that a two-stage betatronic collimation insertion must satisfy to cut the halo of a proton beam down to its ultimate limit which is the aperture of the secondary collimators. Our result is a set of correlated phase advances between primary and secondary collimators. We then determine the number of jaws needed to reach a given level of performance. We also specify the optic of a momentum collimation insertion
Thermal and acoustic effects in CLIC beam absorbers
We study thermal and acoustic effects in the beam absorbers of CLIC. While solid dumps and water at ordinary temperature must be ruled out, we propose to make a dump of water working at 4 degrees centigrades, where the thermal elongation vanishes. This solution might solve the problem of excessive acoustic emission in the dumps which would otherwise prevent the collision of the beams
Optimisation of a Beam Transfer FODO Line
With in view the design of the CLIC long transfer lines, we develop a formal approach for the optimisation of a straight FODO line. Optimum phase advance and cell length depending on beam parameters are derived for power consumption, overall cost and sensitivity to quadrupole misalignment
Spontaneous spinal epidural haematoma during Factor Xa inhibitor treatment (Rivaroxaban)
We report on a 61-year-old female patient who developed a spontaneous spinal epidural haematoma (SSEH) after being treated by rivaroxaban, a new agent for the prevention of venous thromboembolic events in orthopaedic surgery. Although the pathogenesis of SSEH is unclear, anticoagulant therapy is a known risk factor. The patient sustained a sudden onset of severe back pain in the thoracic spine, followed by paraplegia below T8, 2days after proximal tibial osteotomy and rivaroxaban therapy. Magnetic resonance imaging (MRI) of the whole spine demonstrated a ventral SSEH from C2 to T8. Whilst preparing for the emergency evacuation of the SSEH, the neurological symptoms recovered spontaneously 4h after onset without surgery. After monitored bed rest for 48h the MRI was repeated and the SSEH was no longer present. This rare condition of spinal cord compression and unusually rapid spontaneous recovery has not previously been reported following rivaroxaban therap
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