外国人看中国核力量:1964-1996(文章引自Physics Today 2008,第9期)
The Chinese nuclear tests, 1964–1996
A combination of intellectual rigor, technical sophistication, hard work, and intelligence gathering brought China into the world's nuclear club in record-shattering time.
Thomas C. Reed
September 2008, page 47
Nuclear facilities in China
The visitors from China seemed innocuous enough. The five of them had flown in from Beijing to attend the 1989 American Physical Society Conference on Shock Waves in Condensed Matter in Albuquerque, New Mexico. Danny Stillman, director of the technical intelligence division at Los Alamos National Laboratory, met the visitors' plane, took care of their transportation and food needs, and escorted them through the National Atomic Museum in Albuquerque. All five visitors seemed to be jolly academic tourists, but appearances can be—and in this case were—deceptive. In the next year or two, all five were revealed to be top scientists in the Chinese Academy of Engineering Physics, the equivalent of the combined US nuclear weapons laboratories at Los Alamos, Livermore, and Sandia. Those visitors from China were scouting the American turf.
In June of 1988, another guest traveled to Los Alamos by himself: Yang Fujia was a multitasking Chinese technocrat with an ill-defined agenda. (In China, family names come first, and I will observe that custom in the material that follows. The professor's family name is Yang; Fujia is the equivalent of "Tom.") Besides serving as the director of the Shanghai Institute of Nuclear Research, Yang held positions at Fudan University and in several international scientific bodies. Stillman welcomed Yang's visit, for he had learned that the best source of intelligence was often simple and direct questions posed to a knowledgeable visitor.
For starters, Stillman asked the professor, "Does the Chinese nuclear weapons program have a prompt burst reactor?" Such an experimental reactor, typically located in a remote area, can operate supercritically for a fraction of a second and thereby simulate the efflux of radiation and particles from a nuclear detonation. Yang's answer: "Of course."
Stillman pulled out a map of Sichuan Province. "Can you show me where it is?" He thought he already knew the answer, but much to his surprise, Yang pointed to a location off in the mountains, a considerable distance west of the known Chinese nuclear weapons facilities.
Stillman fired a third fastball, right over the plate: "Can you arrange an invitation for me to visit that facility?" "Certainly," the professor responded. "Just send me a copy of your resumé and tell me what other nuclear weapons facilities in China you would like to visit."
Thus began a most remarkable unveiling of the Chinese nuclear weapons program, a deliberate disclosure of its nuclear crown jewels to a central player in the American nuclear intelligence community. Chinese officials knew exactly who Stillman was. It is clear they chose to show him, firsthand, the achievements of their nuclear world. They wanted Stillman to take the information home, to tell the American government, the scientific community, and the citizenry at large all about China's technical capabilities. Why would the Chinese government do that? Nuclear weapons design information is supposed to be a deep, dark secret.
For one thing, the Chinese probably sought deterrence. An American awareness of Chinese nuclear capabilities should lead to a more cautious American military posture around Taiwan and in the Pacific Ocean. Or perhaps it was an intelligence gimmick. Chinese scientists often displayed the inner workings of their technical devices to American visitors just to see how they would react. A raised eyebrow or a sudden scowl could confirm or discount a year's work. Maybe Chinese nuclear technology was no longer top secret. With the coming of Deng Xiaoping's regime around 1980, the proliferation of nuclear technology into the third world had become state policy. Perhaps it was time to let the Americans have a look.
The most likely reason for the Chinese hospitality, however, was a simple yearning for scientific respect. I had found that same phenomenon in the Soviet nuclear weapons laboratories: Excellent scientists, having done incredibly good work for decades, had published nothing. In their lives behind the iron or the bamboo curtain, those scientists had received neither recognition from their countrymen nor accolades from the international scientific community. (See the article "Trinity at Dubna" by myself and Arnold Kramish, PHYSICS TODAY, November 1996, page 30.)
It would take another half decade for the windows to open into the Soviet nuclear world, but the opportunities came faster in China. Mao Zedong died in 1976; within four years Deng Xiaoping had consolidated power and was leading China in new, more pragmatic directions. By the end of the 1980s, perestroika was sweeping the Soviet and Chinese worlds. Chinese leaders were seeking respect from the Western world. By the time the Stillman tours were over, they had earned it.
As an experienced intelligence officer, Stillman made it a point to travel with, and always be in the company of, another American. After a diplomatic delay caused by the difficulties at Tiananmen Square in 1989, Stillman and his intelligence deputy from Los Alamos, H. Terry Hawkins, landed in Shanghai on 3 April 1990.
The first stop was Fudan University, an enormous, fenced, and guarded complex in the northeast quarter of Shanghai. Fudan is home to dozens of research institutes, technical centers, and state-level laboratories. During a tour of one such facility—the Institute of Modern Physics, directed by Yang—bright and motivated students were doing cutting-edge research with antique equipment amazingly acquired in the flea markets of Shanghai. They worked in unheated laboratories, drafty because of broken windows. It was Stillman's first exposure to the contrasting cultures of old and new, a disparity he would encounter often throughout China.
Fudan University was and remains a prime component of the Chinese nuclear weapons complex, with its faculty pursuing research as directed and its best graduates fed into the weapons empire. China has other equally large and prestigious universities—for example, Tsinghua and Beijing universities—but Fudan is still the intellectual fount of nuclear knowledge. While at Fudan, Stillman dined with its then recently retired president, Xie Xide. At that time Xie was a prime example of the interconnected Chinese system: She served in 1990 as chairman of the Shanghai Communist Party Central Committee, which made her the de facto mayor of Shanghai. Earlier, she had graduated from Smith College and MIT; in the immediate future she would assume control of the Center for American Studies at Fudan, part of the vast technical-intelligence system evaluating Western technology. Xie was charming, fluent in colloquial English, and supportive of the Stillman visit, an imprimatur that opened many a door during the weeks that followed.
The next day Stillman visited the Shanghai Institute of Nuclear Research (SINR), also directed by the ubiquitous Yang. That institute employed more than a thousand people, half of them scientists. It had been in existence since 1960. One topic of discussion at the SINR was the mysterious domes of light that had emanated from the Soviet Union's missile test ranges during the previous year. (See box 1 on page 51.) Discussions at the SINR resulted in a gift to Stillman of 35-mm photos (one of which is reproduced in the box) but no explanations. His hosts were puzzled and interested in American thoughts.
Stillman's visit to the SINR also produced his first insight into the extensive hospitality extended to Pakistani nuclear scientists during that same late-1980s time period. As we shall see, that cooperation, initiated earlier in the decade, led to a joint nuclear test in China soon after Stillman's departure.
Chengdu and the inland nuclear empire
The third day of Stillman's visit began with a nerve-wracking experience of air travel in China: The thousand-mile flight from Shanghai to Chengdu, capital of Sichuan Province (site of the devastating magnitude-7.9 earthquake in May 2008) and the heart of the inland nuclear empire, was on an antique Boeing 707. Stillman's guide and interpreter, while assuming the head-between-the-knees position during the harrowing takeoff, assured his guest, "This is a good American airplane. Do not worry." Upon his arrival in Chengdu, Stillman was met by one of the affable Chinese scouts he had first met and hosted in New Mexico the year before. It was only within China that those individuals would reveal their seniority in the Chinese nuclear establishment.
In the following days, the Stillman party traveled by treacherous road from Chengdu to Zitong, Mianyang, and then Science City, the intellectual capital of the blossoming Chinese nuclear empire on Mianyang's outskirts. In talks with his hosts along the way, Stillman came to understand the depth of the 1989 Tiananmen confrontations between generations. At that time, massive riots had erupted throughout China; in Chengdu crowds of students burned buildings while their elders passively looked on, accepting the system as it was.
On the periphery of Science City, Stillman visited a relativistic electron-beam accelerator in an industrialized building equipped with crane hoists capable of positioning large targets. Stillman's hosts acknowledged that the accelerator was used to generate bursts of electromagnetic energy, which simulated a distant nuclear detonation. Those hosts later inquired about US work on x-ray lasers while disclosing their own achievements with prompt burst reactors.
The tour next brought Stillman face-to-face with another of the mysterious visitors to New Mexico: the director of the Southwest Institute of Fluid Physics—a euphemism for the Chinese high explosives test facilities. That institute has access to nine test facilities: three outdoors in the hills well beyond Science City and six containment vessels—large steel spheres that contain the energy released by a few pounds of high explosive. The explosives are wrapped around heavy metals simulating uranium, and the vessels are sealed so as to recover the valuable and sometimes toxic metals involved in the experiment. Four large containment vessels were located in Science City and two smaller ones were housed indoors at the Institute of Applied Physics in Chengdu. All the test facilities were carefully instrumented to collect reams of data. The Chinese scientists were not simply conducting proof-of-principle tests; they wanted to understand the dynamics of nuclear pit implosions.
Entry sculpture at Science City
Science City, the immense central laboratory and office complex that today manages the Chinese nuclear weapons program, was undergoing final completion at the time of Stillman's first visit. It had been constructed during the previous decade to replace the Soviet-planned (and subsequently targeted) complex at Haiyan, well to the north. It was also to replace the intermediate facility at Zitong. At the entrance to Science City stood a towering sculpture symbolizing an exploding nuclear weapon core. Once inside the complex, Stillman found a modern, high-rise administration building, gracious dormitories and guesthouses, the high-explosive test facilities described earlier, a computation center—home to one of China's first supercomputers—and a vast array of experimental laboratories and machine shops. Stillman was warmly greeted. As he was the first American visitor to Science City, his hosts and all their associates were curious, welcoming, and as forthcoming as the security guidelines would allow.
On the road back to the Chengdu airport, modernity was left behind and old China reappeared. Stillman's motorcade encountered a car-wash station along its route. He assumed it reflected some radiological danger left behind in Science City. Not so. The shed turned out to be a tollbooth, operated by a local mountain clan. Even the credentials of foreign dignitaries visiting the heart of the Chinese nuclear weapons complex could not effect a waiver. The government driver could only avoid further delay by paying the "car wash" fee and moving on.