Defense Secretary Harold Brown yesterday downplayed the importance of the now-deferred neutron artillery shells and Lance missile warheads, saying there are "other ways to do the same thing."

Brown suggested that conventional anti-tank weapons and nuclear but non-neutron shells and missile warheads could fill the gap should President Carter decide not to exercise the option of producing neutron weapons.

On "Face the Nation" (CBS, WTOP), Brown described neutron weapons as "useful militarily" but said they would not make "a decisive difference" by themselves in a defense of Western Europe by the North Atlantic Treaty Organization.

Nuclear artillery shells and warheads presently deployed in Europe would destroy enemy tanks, faciliites and personnel through blast and heat. The neutron weapons would destroy their targets primarily by radiation, with high doses penetrating tank armorplate to immediately kill or incapacitate the crew.

Brown was questioned extensively about Carter's decision, announced Friday, to defer production of the neutron versions of the 8-inch shells and Lance warheads, holding that option open while seeing if the Soviet Union responds.

Brown said there were no present plans to specify exactly what concessions the Soviets should make it, but said he expected them to "show restraint" in their "buildup of new equipment," particularly along the NATO front.

Brown added that he believes Secretary of State Cyrus R. Vance in his coming trip to Moscow will be discussing not neutron arms tradeoffs but rather strategic arms limitations.

Brown also said the second part of Carter's neutron decision - preparing for production of new nuclear shells and warheads - is "moving forward."

According to administration sources, a new lance warhead could be in production within 12 months. The 8-inch shell would take perhaps up to 30 months, sources said, because scientists would have to finish development of a 1973 version that was halted when Congress refused to continue funding.

With these production lines going, Brown said only a short time would be needed to add a neutron "feature" should Carter order it.

Congressional critics of Carter's deferral decision have described the neutron weapons as vital to European defense, and have termed the present artillery too destructive and thus unusable.

The nuclear artillery shells now deployed in Europe were first marked for replacement because of their short range - about 10 miles - and their lack of an internal security system which makes them targets for terrorists.

They also are portrayed as complex and slow to load and fire.

Designed to be exploded at 500 feet or more above ground, the current artillery shells were described as recently as 1975 by then Secretary of Defense James Schlesinger as causing little collateral damage.

It was only recently, when the neutron or enhanced radiation feature was adapted from anti-ballistic missile research, that the artillery shell's yield became important.

The neutron versions would provide increased destructive power over the current shell but all in radiation. The current shells would cause much more collateral building damage off the battlefield than the neutron version, though the latter would send more radiation into that same area.

As Brown indicated yesterday, however, artillery shells are only one of several nuclear weapons that would be used in the face of a massive Soviet attack.