Arthur C. Reid, 19, a laboratory technician at the Cambridge Electron accelerator, died at Massachusetts General Hospital Tuesday night of burns and injuries suffered in the July 5 CEA explosion.

Still at MGH last night were Frank Feinberg, 20, M.I.T. '67, in critical condition, and John Schvill, 22, GSAS listed as serious. At Cambridge City Hospital Bent Huld, 25, GSAS, was reported to be in satisfactory condition. The three other explosion victims have been released.

Search Continues

Meanwhile, a team of Atomic Energy Commission investigators continues to search debris in the now roofless CEA experimental hall for clues to the cause of the mysterious blast. Most of the equipment in the hall is coated with tar that dripped from the destroyed roof.

An AEC preliminary report to be issued today, a procedural step in investigations of this nature, reportedly does not name a cause for the explosion or make any changes in the facts as they have been reported up to now.

Chamber Intact

Last night Irwin Pless, professor of physics at M.I.T., who is in charge of the bubble chamber project, said that the bubble chamber appears to be 35 to 90 per cent intact, although "we won't know for sure until we tear it up and look at nuts and bolts."

He said that it would take a year at the most to rebuild the chamber. The 4-year, $1 million project had been in its final stage when the explosion occurred.

Some experts had speculated that the instrument would not be restored. They predicted that by the time it could be finished, the experiments it was built to perform would have been completed elsewhere.

Excess of Work

Although it is true that a scientific instrument such as the bubble chamber or even the accelerator itself does have an almost measurable "halflife" or period of peak usefulness, Pless explained, there is an excess of work for the approximately 15 bubble chambers in the world today.

The chamber is designed to allow experimenters to work with multiple pions and strange particle products by X-rays," Plenn explained.