54616116
PRECISION FIELD MAPPING SYSTEM FOR CYCLOTRON MAGNET
This paper presents a Hall-probe mapping system for measuring the cyclotron magnet, which has been fabricated for the 13 MeV cyclotron at the Korea Institute of Radiological and Medical Sciences(KIRAMS). The Hall probe are mounted on the precision x-y stage, and maps the magnetic field in the Cartesian coordinates. To reduce the data-acquisition time, the system uses the “flying” mode field mapping method. The data acquisition time for mapping the whole gap-area of the cyclotron magnet is ~ 60 minutes. The relative random fluctuation error during the entire mapping process is under 0.01 %. The field measurement results after correction have indicated that the total phase excursion is less than ±15°.
59372197
BEAM SIMULATION OF SQQ INJECTION SYSTEM IN KIRAMS-30 CYCLOTRON ∗
The injection system of KIRAMS-30 cyclotron consists of a doublegap buncher,an SQQ, and a spiral inflector. Initial beam with 100 mmmrad has been generated by random Gaussian function in the transverse plane and random uniform function in the longitudinal direction. Using the 3D electric and magnetic fields of a buncher, SQQ, inflector, and return-yoke bore, the characteristics of the beam injected into the KIRAMS-30 cyclotron’s central region has been obtained. This paper presents the results of its beam characteristics and parameters of each beam element.
56039995
DEVELOPMENT OF BEAM PROFILE MONITOR FOR CYCLOTRON
A current sensor module was designed and fabricated to measure the beam profile of the cyclotron MC50 at KIRAMS. The sensors were made of a tungsten wire and they were assembled into an array type. The sensor wires were placed in parallel with the incident beam, while they were placed in the perpendicular direction to the incident beam in the conventional method. The current output of each sensor was amplified using a transresistance amplifier. The front-end stage of this amplifier was implemented using discrete circuit elements and can measure input current in the range of 1 pA to 1 μA. The amplifier had a resolution of ~ 20 fA and the temperature drift of ~ 0.5 pA/°C. Various test results of the amplifier and sensor module assembly are given in this paper. The measured current profiles of cyclotron beam line at KIRAMS are also given.
23657326
AC Power Supply for Wobbler Magnet of the MC-50 Cyclotron
A wobbler magnet and an AC power supply for the MC-50 cyclotron (k=50) at Korea Institute of Radiological and Medical Sciences (KIRAMS) were designed and constructed to increase the area of beam irradiation. The power supply has two independently operating channels for the vertical and horizontal coils of the wobbler magnet. The frequency of the AC power supply for both coils is programmable from 1 to 20 Hz in a step of 1 Hz, and the maximum output current is 12 A rms. With the wobbler magnet, the uniform irradiation area of the proton beam increased ∼ 4 times larger than the one without the magnet, and various properties of the magnet and power supply system indicate that the system is well suited for many ion beam experiments.
32058981
Development of FTK Architecture: A Fast Hardware Track Trigger for the ATLAS Detector
The Fast Tracker (FTK) is a proposed upgrade to the ATLAS trigger system that will operate at full Level-1 output rates and provide high quality tracks reconstructed over the entire detector by the start of processing in Level-2. FTK solves the combinatorial challenge inherent to tracking by exploiting the massive parallelism of Associative Memories (AM) that can compare inner detector hits to millions of pre-calculated patterns simultaneously. The tracking problem within matched patterns is further simplified by using pre-computed linearized fitting constants and leveraging fast DSP's in modern commercial FPGA's. Overall, FTK is able to compute the helix parameters for all tracks in an event and apply quality cuts in approximately one millisecond. By employing a pipelined architecture, FTK is able to continuously operate at Level-1 rates without deadtime. The system design is defined and studied using ATLAS full simulation. Reconstruction quality is evaluated for single muon events with zero pileup, as well as WH events at the LHC design luminosity. FTK results are compared with the tracking capability of an offline algorithm.
16257249
The fast tracker architecture for the LHC baseline luminosity
A. Annovi,a M. Beretta,a, E. Bossini,b A. Boveia,c E. Brubaker,c F. Canelli,c V. Cavasinni,b F. Crescioli,b H. DeBerg,d M. Dell’Orso,b M. Dunford,c M. Franklin,e P. Giannetti,b A. Kapliy,c Y. K. Kim,c P. Laurelli,a A. McCarn,d C. Melachrinos,c C. Mills,e M. Neubauer,d J. Proudfoot, f , M. Piendibene,b G. Punzi,b F. Sarri,b L. Sartori,bh M. Shochet,c L. Tripiccione,i J. Tuggle,c I. Vivarelli,b G. Volpi∗,b K. Yorita,c J. Zhang. f aINFN Frascati, bUniv. and INFN of Pisa, cUniv. of Chicago, dUniv. of Illinois at Urbana-Champain, eHarvard Univ, f Argonne National Lab, hMarie Curie Fellowship, iUniv. and INFN Ferrara
13022968
Standing Waves in the Lorentz-Covariant World
When Einstein formulated his special relativity, he developed his dynamics for point particles. Of course, many valiant efforts have been made to extend his relativity to rigid bodies, but this subject is forgotten in history. This is largely because of the emergence of quantum mechanics with wave-particle duality. Instead of Lorentz-boosting rigid bodies, we now boost waves and have to deal with Lorentz transformations of waves. We now have some nderstanding of plane waves or running waves in the covariant picture, but we do not yet have a clear picture of standing waves. In this report, we show that there is one set of standing waves which can be Lorentz-transformed while being consistent with all physical principle of quantum mechanics and relativity. It is possible to construct a representation of the Poincaré group using harmonic oscillator wave functions satisfying space-time boundary conditions. This set of wave functions is capable of explaining the quantum bound state for both slow and fast hadrons. In particular it can explain the quark model for hadrons at rest, and Feynman’s parton model hadrons moving with a speed close to that of light.
122338380
COSMIC RAY MUONS FROM LOW GALACTIC LATITUDE
Occasional spurious tracks are found on photographs taken during routine observations with the 40-inch heavy-liquid bubble chamber (HLBC) at the Argonne National Laboratory (Roe, Sinclair, and Vander Vilde 1964). These tracks are caused by cosmic ray muons, and are rather similar to streaks caused by meteors on photographs of the sky. The HLBC is located at Ν 41°42'03" latitude and W 87°59'24" longitude, and at an altitude of 227.38 meters above sea level. It has a field of view in the form of a strip 50° wide centered on the north-zenith-south meridian. The strip extends from horizon to horizon. As the earth turns, 87 percent of the celestial sphere passes through the field of view. The product of the cross-sectional capture area of the HLBC times its field of view is 1.7 meter2 steradian. Each picture covers the entire field of view and has a sensitive time of six milliseconds. The chamber is ex-
56441588
RF noise driven dipole mode parametric resonance
In the Pohang Light Source (PLS) storage ring, we have occasionally experienced the abnormal spontaneous beam. lifetime reduction and strong longitudinal damping. Due to the abnormal beam lifetime reduction, available beam time is reduced substantially. From the recent data analysis of the PLS longitudinal feedback system (LFS) and the streak camera, we have found that the abnormal phenomena can be generated by the RF noise via the dipole mode parametric resonance of the RF phase modulation. We describe the observation of the dipole mode parametric resonance driven by the RF noise and compare it with a simulation result in the PLS storage ring.