新華網(wǎng)日內瓦6月23日電(記者張淼 王昭)歐洲核子研究中心23日發(fā)布新聞公報說，目前全球最大、能量最高的粒子加速器——歐洲大型強子對撞機重啟準備工作已經開始，按計劃對撞機將于2015年初恢復運行。

　　公報稱，為準備重啟，對撞機的冷卻工作已開始，目前對撞機約八分之一部分已冷卻至運行溫度。本月18日，對撞機內部的質子同步加速器已重啟。

　　公報稱，在過去16個月中，大型強子對撞機與歐洲核子研究中心其他加速器經歷了維修與升級，為保證對撞機重啟后按預期能量運行，已在對撞機內部鞏固了1萬個超導磁體。按目前規(guī)劃，對撞機重啟后產生的質子束流能量將是此前運行階段的約兩倍。

　　“在經歷重要‘外科手術’后，大型強子對撞機正從長時間休眠中蘇醒，”歐洲核子研究中心科技和加速器項目主任弗雷德里克·博爾德里說，“我們正在小心喚醒它，爭取在明年初對撞實驗開始前進行諸多測試，2015年的目標是以13萬億電子伏特的質子束流能量進行實驗。”

　　公報稱，大型強子對撞機在首階段運行中以7萬億至8萬億電子伏特的能量進行對撞實驗，重啟后對撞機可能會產生更高的質子束流能量，這將有助于科學家深入研究“上帝粒子”希格斯玻色子，為解開暗物質之謎等開啟新窗口。

　　歐洲大型強子對撞機于2008年9月建成運行，首階段運行于2012年末結束。大型強子對撞機可模擬宇宙大爆炸后的宇宙初期形態(tài)，幫助科學家研究宇宙起源和尋找新粒子。

　　來源：新華網(wǎng) 

　　CERN announces LHC restart schedule

　　The Large Hadron Collider is being prepared for its second three-year run (Image: CERN) 

　　The Large Hadron Collider (LHC), the largest and most powerful particle accelerator in the world, has started to get ready for its second three-year run. Cool down of the vast machine has already begun in preparation for research to resume early in 2015 following a long technical stop to prepare the machine for running at almost double the energy of run 1. The last LHC magnet interconnection was closed on 18 June 2014 and one sector of 1/8 of the machine has already been cooled to operating temperature. The accelerator chain that supplies the LHC’s particle beams is currently starting up, with beam in the Proton Synchrotron accelerator last Wednesday for the first time since 2012.

　　"There is a new buzz about the laboratory and a real sense of anticipation," says CERN Director General Rolf Heuer, speaking at a press conference at the EuroScience Open ForumExternal Links icon (ESOF) meeting in Copenhagen. "Much work has been carried out on the LHC over the last 18 months or so, and it’s effectively a new machine, poised to set us on the path to new discoveries."

　　Over the last 16 months, the LHC has been through a major programme of maintenance and upgrading, along with the rest of CERN’s accelerator complex, some elements of which have been in operation since 1959. Some 10,000 superconducting magnet interconnections of were consolidated in order to prepare the LHC machine for running at its design energy.

　　"The machine is coming out of a long sleep after undergoing an important surgical operation," says Frédérick Bordry, CERN’s Director for Accelerators and Technology. "We are now going to wake it up very carefully and go through many tests before colliding beams again early next year. The objective for 2015 is to run the physics programme at 13 TeV."

　　The LHC experiments also took advantage of this long pause to upgrade their particle detectors. "The discovery of a Higgs boson was just the beginning of the LHC’s journey," said senior CERN physicist Fabiola Gianotti at the same press conference. "The increase in energy opens the door to a whole new discovery potential."

　　The Higgs boson, first mentioned in a 1964 paper by Peter Higgs, is linked to the mechanism, proposed the same year by Higgs and independently by Robert Brout and Fran?ois Englert, that gives mass to fundamental particles. During its first three years, the LHC ran at a collision energy of 7 to 8 TeV delivering particle collisions to four major experiments: ATLAS, CMS, ALICE and LHCb. With the large amount of data provided by the LHC during this first period, the ATLAS and CMS experiments were able to announce the discovery of the long-sought Higgs boson on 4 July 2012, paving the way for the award of the 2013 Nobel Prize in physics to theorists Fran?ois Englert and Peter Higgs.

　　By providing collisions at energies never reached in a particle accelerator before, the LHC will open a new window for potential discovery, allowing further studies on the Higgs boson and potentially addressing unsolved mysteries such as dark matter. The ordinary matter of which we, and everything visible in the universe is composed, makes up just 5% of what the universe is made of. The remainder is dark matter and energy, so the stakes for LHC run 2 are high.

　　CERN’s accelerator complex: Restart schedule 

　　2 June 2014 Restart of the Proton Synchrotron Booster

　　18 June 2014 Restart of the Proton Synchrotron (PS)

　　Early July Powering tests at the Super Proton Synchrotron (SPS)

　　Mid-July Physics programme to restart at the ISOLDE facility and at the PS

　　Mid-August Antimatter Physics programme to restart at the Antiproton Decelerator

　　Mid-October Physics programme to restart at the SPS

　　Early 2015 Beam back into the Large Hadron Collider (LHC)

　　Spring 2015 Physics programme to restart at the LHC experiments

　　Source：home.web.cern.ch