President Reagan's advisers are raising the possibility that he will name a "master negotiator" or arms-control "czar" if reelected as a sign of his determination to negotiate a nuclear accord with the Soviet Union.

Most widely mentioned as a candidate to fill such a post is Brent Scowcroft, national security adviser for President Ford, who became chairman of President Reagan's Commission on Strategic Forces, initially formed to salvage the MX intercontinental missile when it seemed about to be killed two years ago in Congress.

The idea of an arms-control "czar" has been championed for months by moderates in the White House, whose view is that Reagan, though a hard-liner in his first term, "really wants to go down in history as a peace president."

That view has an obvious political advantage in this election season.

It has, those White House advisers pressing it concede, the added advantage of making a virtue out of necessity.

The administration has been plagued by its inability "to knock heads together" among rival policy-makers often at war over strategy and tactics for negotiating arms control.

Throughout the election campaign a major target of Democratic presidential nominee Walter F. Mondale has been Reagan's lack of a nuclear agreement with the Soviet Union.

Campaigning in the Midwest yesterday, Mondale callled the "czar" idea a "public relations gimmick . . . . The United States has a czar for arms control and he's called the president of the United States," Mondale said.

In his Oct. 21 debate with Reagan, Mondale charged him with failure "to lead his government" on arms control, failure "to master" the "essential elements of arms control" and allowing "different people with different views to fight with each other."

By publicly airing the arms-control "czar" idea almost on the eve of the election -- a story about it appeared in The New York Times yesterday -- the administration may have helped to undercut Mondale.

Beyond this, White House moderates, or "pragmatists" as they are often described, led by chief of staff James A. Baker III, have made no secret of their search for a smooth end to the administration's long-standing internal differences over arms control.

Defense Secretary Caspar W. Weinberger and Secretary of State George P. Shultz are principals in the internal dispute.

But the main infighters are Assistant Secretary of Defense Richard N. Perle and Assistant Secretary of State Richard R. Burt, known in the bureaucracy as "the two Richards."

In the middle of the jousting has been national security adviser Robert C. McFarlane.

McFarlane has sought compromise but lacked the power to impose solutions. With Reagan's reluctance to do so, the best McFarlane has been able to achieve has been temporary truces.

By bringing in an outside specialist, "it's a way we can do something without firing anybody," a senior White House adviser said last week.

There is no evidence, however, that Reagan has endorsed the scheme or, for that matter, encouraged it.

A White House spokesman stressed yesterday that it is "a long way" from realization or even a clear definition of what the post would be.

Furthermore, the concept is surrounded by political minefields.

To ultraconservatives in and out of Congress, even the hard line on U.S.-Soviet negotiations championed by the civilian leadership in the Pentagon is regarded as dangerously soft. How the Republican right wing emerges from Tuesday's election, therefore, becomes an important element in the political balance inside the Reagan administration, not only on this issue but on all matters affecting its Soviet strategy.

In Republican ranks, the most obvious potential candidate for an arms-control "czar," Henry A. Kissinger, already has been ruled out, according to Reagan's advisers.

Scowcroft was Kissinger's deputy when Kissinger was President Richard M. Nixon's national security adviser and then his secretary of state, and he was subsequently President Gerald R. Ford's secretary of state. Although Kissinger last month all but advertised his availability for the top arms-control post, he is an anathema to the Republican right wing as the architect of American-Soviet detente in the 1970s.

In an interview last month, Kissinger urged "organizational changes" to end the administration's arms control squabbling and called for creating a bipartisan commission immediately after the election to launch a "crash program" for arms control and a new framework for overall U.S.-Soviet relations.

Furthermore, Kissinger said that if Reagan is reelected, he will be "running for history," free of any further electoral ambitions or constraints, and therefore could concentrate on reaching an arms-control agreement with the Soviet Union as his legacy.

This is the approach stressed by all who urge Reagan to act on arms control.

After taking office as an opponent of every nuclear arms-control pact negotiated by earlier presidents, the move, they apparently feel, would enable him to match, in effect, Nixon's political turnabout in launching American-Soviet detente and the "opening to China."

The president's wife, Nancy, has added her considerable influence to those urging him to take that path. Moreover, Shultz, in a major speech on Oct. 18, stressed the readiness of the administration to launch a "sustained and sound relationship" with the Soviet Union, despite "the fact that the Soviets can be expected periodically to do something abhorrent to us or threaten our interests."

In many respects, however, it would be a far greater turnabout for the Reagan administration to make an agreement with the Soviet Union a top priority than it was for the Nixon administration.

Unlike the Nixon administration, which sought relaxation of tension with the Soviet Union, the Reagan administration is structured to generate challenges to the Soviet Union.

Its hard-line policy-makers, such as Weinberger or Perle, accurately have reflected the president's conviction that the Soviet Union is "an evil empire" which has grossly violated agreements.

Even if the administration does shift its basic approach to the Soviet Union, the technological barriers for reaching accord now are higher than ever before.

The United States and the Soviet Union have been deadlocked on nuclear arms control since the Soviet walkout from two sets of nuclear negotiations in Geneva at the end of 1983 -- the talks on limiting European-based intermediate-range nuclear weapons and the negotiations on limiting strategic, intercontinental-range weapons.

That double stalemate came essentially from Soviet failure to block U.S. installation of Pershing II and cruise missiles in Western Europe, to counter the extensive deployment of Soviet SS20 missiles in Eastern Europe.

During the summer, the United States and the Soviet Union maneuvered without success over a Kremlin proposal to begin a separate negotiation on banning the use of nuclear weapons in space.

The prime Soviet objective was to head off the "Star Wars" drive initiated by Reagan, to develop a space-based defense against nuclear attack.

The nations were unable to agree on terms for beginning those talks, in which the United States also wanted to discuss its priority, limiting offensive weapons, a roundabout approach to the subject of the Geneva negotiations.

Since then, the Soviet leadership has hinted at a willingness for a face-saving compromise on resuming the Geneva talks on offensive weapons.

Both nations have said they will resume attempts to relaunch negotiations after the U.S. election.

Reagan told the United Nations General Assembly on Sept. 24 that "America has repaired its strength," and that now "we are ready for constructive negotiations with the Soviet Union . . . redoubling our negotiating efforts to achieve real results" on all arms-control fronts.