The energy loss of relativistic heavy ions in a gadolinium foil below and above the ferromagnetic Curie temperature

3^rd International Conference on High Energy Physics

December 11-12, 2017 | Rome, Italy

F Nickel

GSI Darmstadt, Germany

Scientific Tracks Abstracts: J Astrophys Aerospace Technol

Abstract :

We report on high-precision measurements (relative accuracy 3 10-5) with the high-resolving mass spectrometer FRS at GSI. Bi ions with an energy of 52 GeV traversed a polycrystalline Gd foil of a thickness of 1.2 mm placed in an external magnetic field of 450 Gauss. The energy loss of these ions after passage the foil was measured as a function of the foil temperature T below and above the ferromagnetic Curie temperature TC of about 19 OC. Further, the macroscopic magnetization M of the used Gd foil was measured as a function of the foil temperature T. The data showed the well-known drop of M approaching TC from lower temperatures. Due to an applied external magnetic field, M does not disappear at TC but exists up-to much higher temperatures reaching 90 OC. Subtraction of effects due to the thermal expansion and due to a measured asymmetric change of the appearing charge-state distribution of the Bi ions when traversing the Gd foil, the remaining relative energy-loss change (�´E/dE)corr increased between 5 OC and 98 OC from 0 to 1.1(5) 10-3. Between 13 OC and 15 OC a sharp increase of 0.26(3) 10-3 was observed. A presentation of (�´E/dE)corr as a function of the negative logarithm of M, namely â��ln M, showed an interesting regular step-wise behavior. Recent Publications 1. Title (2006) Nuclear Instruments and Methods in Physics Research B 243:103-108. 2. F. Nickel (2007) IAE Monographs: Energy loss of swift ions in polycrystalline targets, Vol. 11, Otwock-Swierk, 2007, Poland.