subroutine dawfc(betac,fc)
c     return the 14 fourier coefficients for the disk-and-washer cavity
c     with beta=betac.  the coefficients were determined from superfish
c     runs at 1320 mhz.
      dimension fc(14),beta(13),fct(13,14),wb(13,14),a(13),b(13),
     1 c(13),iop(2),tab(3)
c-----------------------------------------------------------------------
      data iflaga/0/
      data nte/13/
c     fourier coefficients for disk-and-washer cavities, calculated
c      by fitting fields (ez) produced by superfish runs at 1320 mhz.
      data beta(1),(fct(1,i),i=1,14)
     1 / .40,  1.7004098,   .4004310,   .0127821,  -.0107733,
     2    -.0021260,  -.0000018,   .0000623,   .0000091,  -.0000004,
     3    -.0000003,  -.0000000,   .0000000,   .0000000,   .0000000/
      data beta(2),(fct(2,i),i=1,14)
     1 / .45,  1.7138431,   .4365516,  -.0001349,  -.0202500,
     2    -.0034028,   .0003482,   .0002039,   .0000165,  -.0000061,
     3    -.0000015,   .0000001,   .0000001,   .0000000,  -.0000000/
      data beta(3),(fct(3,i),i=1,14)
     1 / .50,  1.7199730,   .4426882,  -.0294735,  -.0335223,
     2    -.0036516,   .0015176,   .0004651,  -.0000206,  -.0000311,
     3    -.0000035,   .0000013,   .0000004,  -.0000000,  -.0000000/
      data beta(4),(fct(4,i),i=1,14)
     1 / .55,  1.7227756,   .4365976,  -.0621659,  -.0449425,
     2    -.0016904,   .0032747,   .0005666,  -.0001767,  -.0000643,
     3     .0000052,   .0000052,   .0000002,  -.0000003,  -.0000000/
      data beta(5),(fct(5,i),i=1,14)
     1 / .60,  1.7175642,   .4002424,  -.1027377,  -.0504709,
     2     .0036487,   .0050321,   .0001544,  -.0004201,  -.0000525,
     3     .0000266,   .0000071,  -.0000010,  -.0000006,   .0000000/
      data beta(6),(fct(6,i),i=1,14)
     1 / .65,  1.7125360,   .3634052,  -.1447630,  -.0537213,
     2     .0116272,   .0066902,  -.0007504,  -.0007375,   .0000333,
     3     .0000722,   .0000012,  -.0000063,  -.0000013,   .0000004/
      data beta(7),(fct(7,i),i=1,14)
     1 / .70,  1.7046153,   .3164490,  -.1866590,  -.0518509,
     2     .0214057,   .0076501,  -.0021739,  -.0010341,   .0001756,
     3     .0001319,   .0000044,  -.0000084,  -.0000039,  -.0000014/
      data beta(8),(fct(8,i),i=1,14)
     1 / .75,  1.6958464,   .2668432,  -.2248376,  -.0422713,
     2     .0326822,   .0059134,  -.0044351,  -.0006683,   .0006081,
     3     .0000552,  -.0000877,   .0000038,   .0000166,  -.0000011/
      data beta(9),(fct(9,i),i=1,14)
     1 / .80,  1.6842016,   .2093434,  -.2575603,  -.0257737,
     2     .0443174,   .0024873,  -.0072979,  -.0000821,   .0012217,
     3     .0000113,  -.0001758,  -.0000079,   .0000186,   .0000052/
      data beta(10),(fct(10,i),i=1,14)
     1 / .85,  1.6711725,   .1482644,  -.2838583,  -.0009840,
     2     .0531696,  -.0054585,  -.0089227,   .0020276,   .0013414,
     3    -.0005137,  -.0001915,   .0001008,   .0000184,  -.0000209/
      data beta(11),(fct(11,i),i=1,14)
     1 / .90,  1.6572213,   .0872635,  -.3011325,   .0277137,
     2     .0572218,  -.0152330,  -.0090068,   .0046492,   .0010017,
     3    -.0011145,   .0000162,   .0002119,  -.0000469,  -.0000304/
      data beta(12),(fct(12,i),i=1,14)
     1 / .95,  1.6419526,   .0264119,  -.3077634,   .0578998,
     2     .0548248,  -.0245994,  -.0062997,   .0064992,  -.0001768,
     3    -.0012938,   .0003311,   .0001860,  -.0001022,  -.0000099/
      data beta(13),(fct(13,i),i=1,14)
     1 /1.00,  1.6285014,  -.0272262,  -.3103627,   .0896837,
     2     .0500958,  -.0358987,  -.0012388,   .0089501,  -.0023262,
     3    -.0013569,   .0009063,   .0000405,  -.0001973,   .0000493/
      if(iflaga.ne.0)go to 20
c     fit splines to fct vs beta for each term
      do 10 i=1,14
      iop(1)=1
      iop(2)=1
      wb(1,i)=0.
      wb(nte,i)=0.
      call spl1d1(nte,beta,fct(1,i),wb(1,i),iop,1,a,b,c)
   10 continue
   20 pi=4.*atan(1.)
      do 30 i=1,14
      call spl1d2 (nte,beta,fct(1,i),wb(1,i),1,betac,tab)
   30 fc(i)=tab(1)
c     normalize coefficients
      sum=0.
      t=1.
      sgn=1.
      do 40 l=1,14
      sum=sum+fc(l)*sgn/t
      t=t+2.
   40 sgn=-sgn
      fac=2.*sum/pi
      do 50 l=1,14
   50 fc(l)=fc(l)/fac
      return
      end
c++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*