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The Relativistic Heavy Ion Collider (RHIC, pronounced like ". The RHIC project had a line-item budget of 616.6 million US Dollar s. The Fiscal Year 2005 operational budget is 106 million US dollars. The total investment by 2005 is approximately 1.1 billion US dollars. While it suffered under the federal budget cut, a key portion of its operational cost in fiscal year 2006 of 13 million US dollars was contributed privately by a group close to Renaissance Technologies of East Setauket, New York . At present, RHIC is the most powerful heavy-ion collider in the world. It is also distinctive in its capability to collide Spin -polarized Proton s. THE ACCELERATOR RHIC is an intersecting Storage Ring (ISR) Particle Accelerator . Two independent rings (arbitrarily denoted as "blue" and "yellow" rings, see also the photograph) allow a virtually free choice of colliding Projectile s. The RHIC double storage ring is itself Hexagon ally shaped and 3834 M long in circumference, with curved edges in which stored particles are deflected by 1,740 Superconducting Niobium Titanium Magnet s. The 6 interaction points are at the middle of the 6 relatively straight sections, where the two rings cross, allowing the particles to collide. The interaction points are enumerated by clock positions, with the injection point at '6 o'clock'. 2 interaction points are unused and left for further expansion (refer also to the RHIC Complex diagram ). A particle passes through several stages of Booster s before it reaches the RHIC storage ring. The first stage for ions is the Tandem Van De Graaff accelerator, while for Proton s, the 200 MeV Linear Accelerator (Linac) is used. As an example, Au nuclei leaving the Tandem Van de Graaff have an energy of about 1 MeV per nucleon and have an electric charge ''Q'' = +32 (32 Electron s stripped from the Au Atom ). The particles are then accelerated by the Booster Synchrotron to 95 MeV per nucleon, which injects the projectile now with ''Q'' = +77 into the Alternating Gradient Synchrontron (AGS), before they finally reach 8.86 GeV per nucleon and are injected in a ''Q'' = +79 state (no electrons left) into the RHIC storage ring over the AGS-To-RHIC Transfer Line (ATR), sitting at the 6 o'clock position. The main types of particle combinations used at RHIC are P + P , D + Au , Cu + Cu and Au + Au . The projectiles typically travel at a speed of 99.995 % of the Speed Of Light in Vacuum . For Au + Au collision, the Center-of-mass energy is typically 200 GeV (or 100 GeV per Nucleon ); a Luminosity of 2 × 1026 Cm -2 S -1 was targeted during the planning. The current luminosity performance of the collider is 2.96 × 1026 cm-2 s-1 ( Run-4 / PHENIX ). A center-of-mass energy of 400 GeV was briefly achieved during Run-5, colliding protons. THE EXPERIMENTS of 100 + 100 GeV/c per nucleon on STAR showing Hadronized charged particle debris curving in the magnetic field of the instrument.]] There are four ", IPA ), PHOBOS (10 o'clock), and BRAHMS (2 o'clock). Three of them are still active, with PHOBOS having completed its operation after 2005 and run-5. Among the two larger detectors, STAR is aimed in the detection of hadrons with its system of dependence in p + p Scattering . The Spokesperson s for each of the experiments are:
CURRENT RESULTS ''For a complementary discussion, see also Quark-gluon Plasma ''. For the experimental objective of creating and studying the quark-gluon plasma, RHIC has the unique ability to provide baseline measurements for itself. This consists of the both lower energy and also lower Mass Number projectile combinations that do not result in the density of 200 GeV Au + Au collisions, like the p + p and d + Au collisions of the earlier runs, and also Cu + Cu collisions in Run-5. Using this approach, important results of the measurement of the hot QCD matter created at RHIC are:
While theorists are eager to claim RHIC as having discovered the quark-gluon plasma (e.g. Gyulassy & McLarren, 2004 ), the experimental groups are more careful not to jump to conclusions, citing various variables still in need of further measurement. A recent overview of the physics result is e.g. provided by Adcox, ''et al.'' (2004) , part of the RHIC Experimental Evaluations 2004 , a community-wide effort of RHIC experiments to evaluate the current data in the context of implication for formation of a new state of matter. These results are from the first three years of data collections at RHIC. THE FUTURE RHIC began operation in 2000 and is currently the most powerful heavy-ion collider in the world. It is expected, however, that the Large Hadron Collider (LHC) of CERN will provide significantly higher energies once completed, essentially superseding RHIC. However, RHIC will likely remain unique in various fields that the LHC in the present state will not be able to cover. Unlike RHIC, LHC is unable to accelerate spin polarized protons, which would leave RHIC remaining as the world's highest energy accelerator for studying spin-polarized proton structure. And ALICE , the dedicated heavy ion detector at LHC, unlike STAR and PHENIX, lacks a Calorimeter for jet tomographic studies. As a result, heavy ion studies with the hadronic detectors of LHC has been proposed (e.g. also a calorimeter upgrade with partial angular coverage has been proposed for ALICE (e.g. [http://nuclear.ucdavis.edu/~jklay/ALICE/EMCAL/ALICE_EMCAL.html , [http://aliceinfo.cern.ch/Collaboration/ALICE_Project/EMCAL/index.html]). Two planned upgrades should enhance the future scientific output of RHIC in these areas:
FEARS AMONG THE PUBLIC Before RHIC started operation, there were fears among the public that the extremely high energy could produce one of the following catastrophic scenarios:
The (extremely) hypothetical theories are complex, but they predict that at least the Earth and the Solar System would be destroyed within seconds. However, the fact that objects of the Solar System (e.g. the Moon ) have been bombarded with Cosmic Particles of significantly higher energies than that of RHIC for billions of years, without any harm to the Solar System, were among the most striking arguments that these hypotheses were unfounded. The other main issue in the controversy was the demand by critics for Physicist s to show an exactly zero Probability for such a catastrophic scenario, which physics cannot provide. However, by following the same argument of the critics, and using the same experimental and Astrophysical constraints, physicists are also unable to demonstrate a zero probability, but just an upper limit for the likelihood, that tomorrow Earth will be struck with a " Doomsday " cosmic ray, resulting in the same destructive scenarios. According to this argument of upper limits, RHIC would still modify the chance for the Earth's survival by an extremely marginal amount. The debate started in convened by the Director of Brookhaven National Laboratory, J. H. Marburger , ruling out the catastrophic scenarios depicted (R. Jaffe ''et al.'', 2000). W. L. Wagner tried subsequently – as he had attempted with various accelerators before – to stop full energy collision at RHIC by filing Federal lawsuits in San Francisco and New York , but without success (see e.g. {Link without Title} ). On matter created in RHIC to a black hole is only in the sense of a correspondence of QCD scattering in Minkowski Space and scattering in the ''AdS''5 × ''X''5 space in AdS/CFT ; in other words, similar mathematically. RHIC collisions therefore might be useful to study Quantum Gravity behavior within AdS/CFT, but the described physical phenomena are not the same. RHIC IN FICTION The novel ''Cosm'' () by the American author Gregory Benford takes place at RHIC. The Science Fiction setting describes the main character Alicia Butterworth, a physicist at the BRAHMS experiment, and a new Universe being created in RHIC by accident, while running with Uranium ions (see {Link without Title} , page 2). REFERENCES
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