President Carter met yesterday with his top foreign policy and defense advisers to hear their proposals for alternatives to outright cancellation of neutron weapons production.

Meanwhile, adverse reactions continued to pour into the White House from Congress in response to disclosure that in the past two weeks, Carter reversed his earlier position favoring production of the new generation of tactical nuclear weapons.

Leaders of the House Armed Serices Committee, who had led last year's fight that ended with overwhelming House support of the neutron weapons, yesterday drafted a letter to the president drafted a letter to the president that argued against a ban on their production.

Secretary of State Cyrus R. Vance, Defense Secretary Harold Brown and White House national security affairs adviser Zbigniew Brzezinski attended yesterday afternoon's session with the president.

All three reportedly were pressing for a presidential decision that would preserve the option of going ahead with production of neutron 8-inch artillery shells and Lance missile warheads while attempting to use them as bargaining chips with the Soviet Union in arms control negotiations.

"This is not the moment of decision," one source said yesterday in cautiously describing yesterday's session.

Presidential press secretary Jody Powell told reporters yesterday there was no deadline set for a decision on whether Carter will order production of neutron 8-inch artillery shells and Lance missile warheads.

Powell did say there would be more consultations with NATO allies and with members of Congress though he added they "won't drag on."

Carter had initially promised to make his decision seven months ago.

Since then, administration officials have been negotiating with NATO allies over their public support for a Carter production decision and agreement that once built the weapons would be deployed on European soil.

Political opposition in Western Europe to the weapons has made NATO leaders hesitant about making any public pronouncements of the type Carter desired.

Three weeks ago a go-ahead from the President on production of neutron weapons seemed inevitable.

At that time, according to informed sources, Carter and his closest aides took their first long, serious look at the problems created by such a decision.

The result of Carter's personal review, in which his chief aide, Hamilton Jordan, played a role, was to reverse direction and begin exploration of what would happen if the program were ended before any weapons were produced.

Deputy Secretary of State Warren Christopher was ordered to tell West German Chancellor Helmut Schmidt that Carter was "seriously inclined" against production.

Meanwhile in Washington preparations were made hastily for announcing a Carter end to the neutron program.

Schmidt's unhappy response to Christopher's message and recent publication of Carter's reversal have thrown the whole matter into turmoil.

One factor that impressed Carter was the impact it would have on his appearance at next month's United Nations special sesion on disarmament.

"Carter may have had a hard time thinking of himself up there talking about disarmament," one administration source said, "and being the president who had ordered production of a new type of nuclear weapon."

There were also questions raised about the military advantage of the neutron 8-inch shell. It had been oversold to the public as vital to NATO defenses but Defense Secretary Brown termed it only "desirable."

Also yesterday, for the first time, the high cost of neutron weapons was suggested by Powell as one area of concern in Carter's assessment of his production decision.

According to informed sources, each 8-inch neutron shell would cost almost $1 million and the entire purchase would come to over $43 million just to cover the cost of building special production facilities for the shell.

Opponents of neutron weapons within the government have in the past often pointed out their high cost in relation to other weapons. For example, the cost of the 8-inch conventional nuclear shell is less than half that of the neutron shell, according to an informed source.

In addition to te House Armed Services Committee leadership, other congressional voices were also raised against an end to the neutron program.

Senate majority Leader Robert C. Byrd (D-W. Va.) told Carter at the morning's congressional breakfast at the White House that he believed the weapons should be built.

Rep. Bob Wilson (R-Calif.) ranking GOP member on the Armed Services panel, said yesterday Carter "would be mistaken to abandon the neutron [weapons] at this late date."