Changing the quad settings
facet home → Profile Monitor → LI20 → SPEC LINE GUI
...
- Leave big "Dipole" switch in "Without" setting (dipole energy is not adjusted)
- Set "Z Object" to the position where the beam should be imaged, e.g., the center of the PB
- Set "Z Image" to the position of the screen, e.g., z=2015.26 for DTOTR
- M12, M34: transfer-matrix elements (set both to 0 for re-imaging)
- Energy: determines where the focus is
- Press "Calculate and Trim"
...
...
...
Assumptions of this script:
- Magnet length: 1m
LEFF_QS0 = 1; % [m]
LEFF_QS1 = 1; % [m]
LEFF_QS2 = 1; % [m] - Quad positions:
z_QS0 = 1996.98249; % [m], middle of quad
z_QS1 = 1999.206615; % [m], middle of quad
z_QS2 = 2001.431049; % [m], middle of quad - Other important positions:
1993.27370 # [m] FILS
1992.82000 # [m] PIC_CENT
2015.62984 # [m] LFOV
2017.52998 # [m] PRDMP
Changing the dipole settings
- It is important that the e-beam never passes through the CsI array (see Dump-table electron diagnostics)
- Call ACR for changing the main dipole
FACET script to calculate quad settings (E300_calc_QS_3.mat, Nov 13, 2023)
function [isok, BDES0, BDES1, BDES2] = E300_calc_QS_3(z_ob, z_im, QS, m12_req, m34_req)keep_KQS0_eq_KQS2=1; % set to one if QS0=QS2
E0 = 10;
isok = 1;
if(nargin < 4); m12_req = 0; end;
if(nargin < 5); m34_req = 0; end;% initial guesses (2012 values)
KQS0_0 = -0.3;
KQS1_0 = 0.23;
KQS2_0 = -0.3;
mytol = (0.01^2 + 0.01^2 );% linac z locations of QS1 and QS2
z_QS0 = 1996.98249; % [m], middle of quad
z_QS1 = 1999.206615; % [m], middle of quad
z_QS2 = 2001.431049; % [m], middle of quadLEFF_QS0 = 1; % [m]
LEFF_QS1 = 1; % [m]
LEFF_QS2 = 1; % [m]OO = zeros(2,2);
d1 = (z_QS0-LEFF_QS0/2) - z_ob ;
d2 = (z_QS1-LEFF_QS1/2) - (z_QS0+LEFF_QS0/2);
d3 = (z_QS2-LEFF_QS2/2) - (z_QS1+LEFF_QS1/2);
d4 = z_im - (z_QS2+LEFF_QS2/2);M_01 = [1 d1; 0 1];
M4_01 = [M_01 OO; OO M_01];
M_02 = [1 d2; 0 1];
M4_02 = [M_02 OO; OO M_02];
M_03 = [1 d3; 0 1];
M4_03 = [M_03 OO; OO M_03];
M_04 = [1 d4; 0 1];
M4_04 = [M_04 OO; OO M_04];
options = optimset('TolX',1e-8);
if keep_KQS0_eq_KQS2
[fit_result, chi2] = fminsearch(@transportError_2, [KQS0_0 KQS1_0],options);
BDES0 = fit_result(1) * (E0+QS) * LEFF_QS0 / 0.0299792458;
BDES1 = fit_result(2) * (E0+QS) * LEFF_QS1 / 0.0299792458;
BDES2 = fit_result(1) * (E0+QS) * LEFF_QS2 / 0.0299792458;
else
[fit_result, chi2] = fminsearch(@transportError, [KQS0_0 KQS1_0 KQS2_0],options);
BDES0 = fit_result(1) * (E0+QS) * LEFF_QS0 / 0.0299792458;
BDES1 = fit_result(2) * (E0+QS) * LEFF_QS1 / 0.0299792458;
BDES2 = fit_result(3) * (E0+QS) * LEFF_QS2 / 0.0299792458;
end
if(chi2 > mytol)
isok = 0;
warning('could not converge to solution');
BDES0 = NaN;
BDES1 = NaN;
BDES2 = NaN;
endBMAX = 385; % max value, from SCP
if(abs(BDES1) > BMAX || abs(BDES2) > BMAX || abs(BDES0) > BMAX)
isok = 0;
warning('solution is outside QS range');
end%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function chi2 = transportError(K)
% QS0 transport matrix
k = abs(K(1));
phi = LEFF_QS0*sqrt(k);
M_F = [cos(phi) (1/sqrt(k))*sin(phi)
-sqrt(k)*sin(phi) cos(phi)];
M_D = [cosh(phi) (1/sqrt(k))*sinh(phi)
sqrt(k)*sinh(phi) cosh(phi)];
M4_D1 = [M_D OO; OO M_F];
% QS1 transport matrix
k = abs(K(2));
phi = LEFF_QS1*sqrt(k);
M_F = [cos(phi) (1/sqrt(k))*sin(phi)
-sqrt(k)*sin(phi) cos(phi)];
M_D = [cosh(phi) (1/sqrt(k))*sinh(phi)
sqrt(k)*sinh(phi) cosh(phi)];
M4_F = [M_F OO; OO M_D];
% QS2 transport matrix
k = abs(K(3));
phi = LEFF_QS2*sqrt(k);
M_F = [cos(phi) (1/sqrt(k))*sin(phi)
-sqrt(k)*sin(phi) cos(phi)];
M_D = [cosh(phi) (1/sqrt(k))*sinh(phi)
sqrt(k)*sinh(phi) cosh(phi)];
M4_D2 = [M_D OO; OO M_F];% dump line optics
M4 = M4_04*M4_D2*M4_03*M4_F*M4_02*M4_D1*M4_01;
chi2 = (M4(1,2)-m12_req)^2 + (M4(3,4)-m34_req)^2;
endfunction chi2 = transportError_2(K)
% QS0 transport matrix
k = abs(K(1));
phi = LEFF_QS0*sqrt(k);
M_F = [cos(phi) (1/sqrt(k))*sin(phi)
-sqrt(k)*sin(phi) cos(phi)];
M_D = [cosh(phi) (1/sqrt(k))*sinh(phi)
sqrt(k)*sinh(phi) cosh(phi)];
M4_D1 = [M_D OO; OO M_F];
% QS1 transport matrix
k = abs(K(2));
phi = LEFF_QS1*sqrt(k);
M_F = [cos(phi) (1/sqrt(k))*sin(phi)
-sqrt(k)*sin(phi) cos(phi)];
M_D = [cosh(phi) (1/sqrt(k))*sinh(phi)
sqrt(k)*sinh(phi) cosh(phi)];
M4_F = [M_F OO; OO M_D];
% QS2 transport matrix
k = abs(K(1));
phi = LEFF_QS2*sqrt(k);
M_F = [cos(phi) (1/sqrt(k))*sin(phi)
-sqrt(k)*sin(phi) cos(phi)];
M_D = [cosh(phi) (1/sqrt(k))*sinh(phi)
sqrt(k)*sinh(phi) cosh(phi)];
M4_D2 = [M_D OO; OO M_F];% dump line optics
M4 = M4_04*M4_D2*M4_03*M4_F*M4_02*M4_D1*M4_01;
chi2 = (M4(1,2)-m12_req)^2 + (M4(3,4)-m34_req)^2;
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%end