This discrepancy is due to the tau blindspots in Mims ENDOR as simulated by
saffron
, which are not included in the
salt
simulation. You can see this by setting tau to a very small value (1 ns or less), which removes all blind spots except the central one. If you set tau to a very large value (10 microseconds say) and you have enough spectral points, you will see that the Mims ENDOR spectrum approaches the
salt
spectrum. Any remaining small differences are due to the fact that one is a CW simulation and the other is a pulse simulation.
Here is a simple script you can use to explore this:
Code: Select all
clear
B0 = 1215.8; % mT
mw = 34.087; % GHz
tau = 10;
Exp.mwFreq = mw;
Exp.Range = [6.5 9.5]; % MHz
Exp.nPoints = 1000;
Exp.ExciteWidth = 30;
Exp.Field = B0;
Sys.g = [2.008, 2.003, 2.003];
Sys.lw = 0.08;
Sys = nucspinadd(Sys,'2H',[1.2 1.2 0.2],[0 0 0]*pi/180);
Sys.lwEndor = 0.05;
Opt.ProductRule = 1;
Opt.nKnots = 91;
% Mims ENDOR spectrum, saffron
Exp_ = Exp;
Exp_.Sequence = 'MimsENDOR';
Exp_.tau = tau;
[freqs,ysaff] = saffron(Sys,Exp_,Opt);
ysaff = ysaff/max(ysaff);
% CW ENDOR spectrum, salt
[freqs,ysalt] = salt(Sys,Exp_,Opt);
ysalt = ysalt/max(ysalt);
% Frequency-domain EPR spectrum
FSExp.mwRange = [33.9 34.3];
FSExp.Field = B0;
FSExp.Harmonic = 0;
FSOpt.Output = 'summed';
[xfs,yfs] = pepper(Sys,FSExp,FSOpt);
yfs = yfs/max(yfs);
% plotting
clf
subplot(2,1,2)
plot(freqs,ysalt,'color','b')
hold on
plot(freqs,ysaff,'color','r')
line([1 1]*larmorfrq('2H',B0), ylim);
legend('salt','saffron');
legend boxoff
xlabel('frequency (MHz)');
subplot(2,1,1);
plot(xfs,yfs)
line([1 1]*Exp.mwFreq,ylim,'Color','k');
xlabel('frequency (GHz)');