scholarly journals Phase space growth during RF capture in the GSI heavy ion synchrotron SIS-18

2003 ◽  
Vol 21 (1) ◽  
pp. 85-89
Author(s):  
M. KIRK ◽  
H. DAMERAU ◽  
I. HOFMANN ◽  
O. BOINE-FRANKENHEIM ◽  
P. SPILLER ◽  
...  
Keyword(s):  
Phase Space ◽  
Nuclear Research ◽  
Heavy Ion ◽  
Beam Current ◽  
Current Profile ◽  
Momentum Spread ◽  
European Organization ◽  
Frequency Capture ◽  
A Value ◽  
Ion Species

This study reports on the optimization of the radio frequency capture phase during the operational cycle of the SIS-18 synchrotron at Gesellschaft für Schwerionenforschung, Darmstadt, Germany. The ion species studied were 238U+28 and 238U73+ at an injection energy of 11.4 MeV/u. The longitudinal relative momentum spread derived from Schottky spectra of the coasting beam at injection provides a value of |Δp/p0|full-width ∼ 5 × 10−3. Simulation results from the synchrotron tracking code ESME (FermiLab) were compared with beam-current profile measurements obtained from a pickup. To gain further insight, the Tomography program (European Organization for Nuclear Research) has been used to derive the longitudinal phase space development from waterfall plots of the measured beam current profile, which may then be compared against simulation. Possible causes of this nonadiabaticity are discussed and solutions are proposed.

scholarly journals Beam losses in heavy ion drivers

2002 ◽  
Vol 20 (4) ◽  
pp. 637-640 ◽  
Author(s):  
E. MUSTAFIN ◽  
O. BOINE-FRANKENHEIM ◽  
I. HOFMANN ◽  
P. SPILLER
Keyword(s):  
Nuclear Research ◽  
Heavy Ion ◽  
Beam Current ◽  
Relativistic Heavy Ion Collider ◽  
European Organization ◽  
Beam Loss ◽  
Secondary Neutron ◽  
Experimental Physics ◽  
Heavy Ion Fusion ◽  
Good Agreement

While beam loss issues have hardly been considered in detail for heavy ion fusion scenarios, recent heavy ion machine developments in different labs (European Organization for Nuclear Research(CERN), Gesellschaft für Schwerionenforschung (GSI), Institute for Theoretical and Experimental Physics (ITEP), Relativistic Heavy-Ion Collider (RHIC)) have shown the great importance of beam current limitations due to ion losses. Two aspects of beam losses in heavy ion accelerators are theoretically considered: (1) secondary neutron production due to lost ions, and (2) vacuum pressure instability due to charge exchange losses. Calculations are compared and found to be in good agreement with measured data. The application to a Heavy-Ion Driven Inertial Fusion (HIDIF) scenario is discussed.

scholarly journals Chemical and Temperature Inhomogeneities on Stellar Surfaces as a Result of an Instability

1986 ◽  
Vol 90 ◽  
pp. 395-396
Author(s):  
A.Z. Dolginov
Keyword(s):  
Hydrogen Plasma ◽  
Heavy Ion ◽  
Space Distribution ◽  
Magnetic Traps ◽  
Rare Elements ◽  
A Value ◽  
Long Time ◽  
Chemical Anomalies ◽  
Ion Species ◽  
The Magnetic Field

Observations show that chemical anomalies are distributed inhomogeneously on Ap star surfaces. The most elaborated explanation of the observations is based on the fact that different ions and atoms are affected by radiative forces of different strengths and, hence, have different diffusion velocities. The diffusion across the magnetic field is a factor of (l + νH2/νC2)−1 slower than along the field (νH is the gyrofrequency and νC is the collision frequency of the ions). It leads to the increasing of the heavy ion number density in regions occupied by magnetic traps.However, such an explanation meets a number of difficulties: a) the conditions holds for the most of ion species only in regions where the optical depth is less than 10−2 if the field H exceeds 105 gs. Although little is known on the depth of the region occupied by the chemical anomalies, there are some indirect indications that it is larger than 10−2; b) The observed dipole field has a value 103−104 gs and does not form traps corresponding to the observed chemical spots which have very complicated configurations; c) the magnetic trap is imperfect. The separation process in the field is assumed to be produced by the diffusion which needs a long time. However, ions can escape from the trap together with the surrounding hydrogen plasma because of various plasma instablished which take much shorter time; d) observed space distribution of rare elements and also of Fe, Cr, Ti contradicts the predictions of the magnetic separation hypothesis (cf. V. Khohlova IAU Coll. No. 90, this volume).

scholarly journals Phase-space density in heavy-ion collisions revisited

2003 ◽  
Vol 30 (4) ◽  
pp. 517-523 ◽  
Author(s):  
Q. H. Zhang ◽  
J. Barrette ◽  
C. Gale
Keyword(s):  
Phase Space ◽  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Phase Space Density ◽  
Space Density ◽  
Ion Collisions

scholarly journals Large Hadron Collider as a Legal Phenomenon

Lex Russica ◽  
2019 ◽  
pp. 161-173 ◽  
Author(s):  
A. O. Chetverikov
Keyword(s):  
Large Hadron Collider ◽  
Legal Status ◽  
Hadron Collider ◽  
Nuclear Research ◽  
European Organization ◽  
History Of Development ◽  
Scientific Organizations ◽  
Legal Nature ◽  
History Of ◽  
Scientific Collaborations

   Сontinued. See: LEX RUSSICA. 2019. № 4. Pp. 151—169This paper is the first in Russia comprehensive theoretical and practical study of one of the world’s largest international scientific installations of the «megasience» class — the Large Hadron Collider (LHC) — from the standpoint of legal science.The author focuses on the unique legal status and legal nature of international scientific collaborations, with the help ofwhichscientistsfromdozensofcountries, including Russia, carry outresearchandmakescientificdiscoveries on the LHC. The paper considers and analyzed the following: the history of development, general principles of the LHC and the European organization for nuclear research (CERN), under the auspices of which its construction was carried out; the principles of the structure and functioning of international scientific collaborations around the LHC; the legal nature of their constituent documents as acts of soft law; the ratio of soft and hard law mechanisms in the regulation of international scientific collaborations around the LHC.The final section presents data and proposals on the use of the legal mechanisms studied in other countries and international organizations, including for the purpose of the construction of scientific installations of the «megasience» class under the auspices of the national scientific organizations of Russia and the Joint Institute for Nuclear Research in Dubna (Moscow region).

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