View source for HRRL 03-17-2011

= Accelerator Tuning =
= Good Tune Used for good Scan =

By Dr. Kim

{| border="1"
| Solenoid 1     || 6.8 A 
|-
|Solenoid 2      ||   10.4 A
|-
|Gun Ver         || -0.2 A
|-
| Gun Hor        || +0.4 A
|-
|Output Hor      || -1.4A
|-
| Output Ver     || -0.5 A

|-
|   Gun HV   || +9.75 (Knob Setting)
|-
|   Gun Grid Voltage   || 5.25 (Knob Setting)
|-
|   RF frequency   || 2855.816 MHz
|-
|   Modulator HV Power Supply   || 4.42 (Knob Setting)
|-
|  RF macro Pulse Length (FWHM)  || 200 ns
|-
|  Peak Current on FC    || 37.2 mAmps
|-
|  Scope on FC   || [[File:Scope_image_of_good_Accelarator_setting_by_Dr._Kim_Mar_17_2011.png | 100 px]]
|-
|  e- Beam Energy   || 14 MeV


|}

= Scan Description =

This is scan for 14 MeV beam. 40 mAmps peak current. Q1 is on, All other quads are off.

1) Scan from -5 Amps to 5 Amps

2) Increment at 0.2 Amps.

3) Name images by numbers start from 1. Then go on. 

Like: -5 Amp is 1, -4.8 Amp is 2, and so on til 5 Amp is named 51.

4) Scan multipole times from -5 to 5 Amps, and put them in different folders.

5) For each time, take back ground images. It should be done when RF is on and gun is off.

6) After the scan take a scope image for the current of the FC after the OTR screen.

= Calibration =


{| border="3"  cellpadding="20" cellspacing="0"
| image || OTR image || cal_h (mm/px) || cal_v (mm/px)
|-
|[[File:HRRL_03-17-2011_cal_1_source.png | 200 px]]  || [[File:HRRL_03-17-2011_cal_1.png | 200 px]]   ||  0.04308   ||0.04204
|-
|[[File:HRRL_03-17-2011_cal_2_source.png | 200 px]]  || [[File:HRRL_03-17-2011_cal_2.png | 200 px]]   ||  0.04320   ||0.04228
|-
|[[File:HRRL_03-17-2011_cal_3_source.png | 200 px]]  || [[File:HRRL_03-17-2011_cal_3.png | 200 px]]   ||  0.04349   ||0.04181
|-
|[[File:HRRL_03-17-2011_cal_4_source.png | 200 px]]  || [[File:HRRL_03-17-2011_cal_4.png | 200 px]]   ||  0.04323   ||0.04196
|-
|[[File:HRRL_03-17-2011_cal_5_source.png | 200 px]]  || [[File:HRRL_03-17-2011_cal_5.png | 200 px]]   ||  0.04337   ||0.04212
|-
|  || || mean (mm/px) || mean (mm/px) 
|-
|  || || <math> 0.04327 \pm 0.00016 </math>||  <math>  0.04204 \pm  0.00018 </math> 
|}


= Results =
== Q1 ==

At lower current background subtraction gets worse, because singal/noise drops.

=== 42 mA, Positive Current, X projection ===

emit=0.388 +- 0.008 mm*mrad, emit_norm=10.64 +- 0.22 mm*mrad 

beta=1.285 +- 0.024, alpha=0.94 +-0.03 



[[File:HRRL 03-17-2011_Results_Q1_42mA_Pos_SupGau_X.png | 300 px]]

 //K1*L(1/m)   er K1*L    sgima^2(mm)   er sigma^2

[[Media:2011_Mar_Emit_fit_data_x.txt]]



parabola fit for x-projection: 
 
parabola fit for y-projection (y in mm unit): 

y = (3.69167 +-0.02346) + (-3.89000+-0.12250)*x + (4.79738+-0.13309)*x.*x 
 

Data created from parabola fit

[[Media:2011_Mar_Emit_data_from_fit_x.txt]]




=== 42 mA, Negative Current, Y projection ===

emit=0.266 +- 0.018 mm*mrad, emit_norm=7.30 +- 0.50 mm*mrad 

beta=0.918 +- 0.068, alpha=0.19 +-0.06 


[[File:HRRL 03-17-2011_Results_Q1_42mA_Pos_SupGau_Y.png | 300 px]]

 //K1*L(1/m)   er K1*L    sgima^2(mm)   er sigma^2

[[Media:2011_Mar_Emit_fit_data_y.txt]]


parabola fit for y-projection (y in mm unit): 

y = (2.81806 +-0.03890) + (0.52202+-0.26284)*x + (2.35025+-0.34553)*x.*x 

Data created from parabola fit

[[Media:2011_Mar_Emit_data_from_fit_y.txt]]



X and Y emittances are different. The parabola in X reaches min around 0.4, while in Y reaches around 0.15. Which suggests quadrupole strengths of  X and Y are way different for same coil current. Which might suggest beam is not centered, because when beam is off-centered we have this can occur.













=== 20 mA, Positive Current, X projection ===

[[File:HRRL 03-17-2011_Results_Q1_20mA_Pos_SupGau_X.png | 300 px]]



[[File:HRRL 03-17-2011_Results_Q1_20mA_Pos_SupGau_Y.png | 300 px]]



=== 10 mA, Positive Current, X projection ===

[[File:HRRL 03-17-2011_Results_Q1_10mA_Pos_SupGau_X.png | 300 px]]



[[File:HRRL 03-17-2011_Results_Q1_10mA_Pos_SupGau_Y.png | 300 px]]

=== 5 mA, Positive Current, X projection ===

[[File:HRRL 03-17-2011_Results_Q1_5mA_Pos_SupGau_X.png | 300 px]]


[[File:HRRL 03-17-2011_Results_Q1_5mA_Pos_SupGau_Y.png | 300 px]]

== Q4 ==

=== 42 mA All Other Quads off ===

Haven't reach minimum.

=== 42 mA Q1_at_-2A, Q2_at_+8A, Q3_at_-6A ===


[[File:HRRL 03-17-2011_Results_Q4_42mA_T1_On_Pos_SupGau_X.png | 300 px]]

x-projection:


[[File:HRRL 03-17-2011_Results_Q4_42mA_T1_On_Pos_SupGau_Y.png | 300 px]]

y-projection:



= Fits After the Second Mapping of the Quad  =

I mapped the quad to find effective length of the quad for different currents. Results are at: [[Second Mapping of Quadruple Magnets]]



== MATLAB Scripts ==

[[Media:hrrl_2011_marc_emit_test_marc17_SuperGaussian_Fit.txt]]

[[Media:hrrl_2011_marc_emit_test_marc17_SupGau_devsum.txt]]

[[Media:hrrl_2011_marc_emit_test_marc17_Emit_Parabola_Fit_kl_XProjection.txt]]

[[Media:hrrl_2011_marc_emit_test_marc17_Emit_Parabola_Fit_kl_YProjection.txt]]



[[Media:hrrl_2011_marc_emit_test_marc17_Trial_my_superGaussian_Fit.txt]]

[[Media:hrrl_2011_marc_emit_test_marc17_Plot_Beam_Spot.txt]]

[[Media:hrrl_2011_marc_emit_test_marc17_Three_d_surface_plotter.txt]]

[[Media:hrrl_2011_marc_emit_test_marc17_my_superGaussian_Fit.txt]]

[[Media:hrrl_2011_marc_emit_test_marc17_devsum.txt]]

[[Media:hrrl_2011_marc_emit_test_marc17_countor_plotter.txt]]

== With thin lens approximation method ==

 Why y projection has bigger error?

 For data look at here: [[HRRL-03-17-2011-fit-error-ana]]
 
 From the data we can see that sigma (rms) of Y-projection are more spread, 
 ie. has bigger standard deviation, than the of X-projection. 

 I think this is due to the beam profile in Y-projection contains less pixels than X- projection. 
 (This is due to Y-projection observed with 45 degree angle, so Y-profile got squeezed).

 So, Y-projection has less data for fitting, thus this creates bigger standard deviation for sigma (rms) value of the Y-projection.


Quad was mapping for the second time to find effective length for the different currents. Link is at [[https://wiki.iac.isu.edu/index.php/Second_Mapping_of_Quadruple_Magnets]].

=== X ===
[[File:HRRL_Pos_Emit_test_Mar17_2011_Fit_after_2nd_quad_mapping_q1.png | 300 px]]

x-projection:

emit=0.369 +- 0.019 mm*mrad, emit_norm=10.10 +- 0.51 mm*mrad 

beta=1.40 +- 0.06 m, alpha=0.97 +- 0.06 rad 

parabola fit for y-projection (y in mm unit): 
 y = (3.23007 +-0.01742) + (-3.70339+-0.17170)*x + (4.94449+-0.33370)*x.*x 


<math> \sigma_x^2= (  \pm ) + ( \pm )k_1L + ( \pm )(k_1L)^2 </math>

<math> \epsilon_x =  \pm ~mm*mrad ~\Rightarrow~ \epsilon_{n,x} =  \pm ~mm*mrad</math>

<math> \beta_x= \pm , \alpha_x= \pm  </math>

=== Y ===

[[File:HRRL_Pos_Emit_test_Mar17_2011_Fit_after_2nd_quad_mapping_q2.png | 300 px]]

y-projection:

emit=0.294 +- 0.038 mm*mrad, emit_norm=8.06 +- 1.05 mm*mrad 

beta=1.17 +- 0.13 m, alpha=0.24 +- 0.07 rad 

parabola fit for y-projection (y in mm unit): 
 y = (2.47210 +-0.02580) + (0.78376+-0.30261)*x +(3.29515+-0.73747)*x.*x 




<math>\sigma_y^2 = ( \pm ) + ( \pm )k_1L + ( \pm )(k_1L)^2 </math>

<math> \epsilon_y =  \pm ~mm*mrad  ~\Rightarrow~  \epsilon_{n,y} =  \pm ~mm*mrad</math>

<math> \beta_y= \pm , \alpha_y= \pm  </math>







= Energy Measurement =

{| border="3"  cellpadding="20" cellspacing="0"
| Dipole Current (A)|| Beam Energy (MeV) || FC current image || Current (mA)
|-
| 30.0000  ||  14.6469  || [[File:hrrl_17Mar2011_En_Scan_30MeV.png | 400 px]] || 0.6
|-
| 30.5000 ||   14.8240 ||  [[File:hrrl_17Mar2011_En_Scan_30p5MeV.png | 400 px]] || 1.2
|-
| 31.0000  ||  14.9985  || [[File:hrrl_17Mar2011_En_Scan_31MeV.png | 400 px]] || 3.2
|-
| 31.5000 ||   15.1704   || [[File:hrrl_17Mar2011_En_Scan_31p5MeV.png | 400 px]] || 3.0
|-
| 32.0000  ||  15.3398   || [[File:hrrl_17Mar2011_En_Scan_32MeV.png | 400 px]] || 2.4
|-
| 32.5000 ||   15.5066   || [[File:hrrl_17Mar2011_En_Scan_32p5MeV.png | 400 px]] || 1.3
|-
| 33.5000  ||  15.8325   || [[File:hrrl_17Mar2011_En_Scan_33p5MeV.png | 400 px]] || 0.4
|-
|}

 Energy     Current
 (MeV)      (mA)
 14.6469    0.6
 14.8240    1.2
 14.9985    3.2
 15.1704    3.0
 15.3398    2.4
 15.5066    1.3
 15.8325    0.4


Here used dipole mapping [[Kiwi_Dipole_Mappings#Estimation_for_En_vs_I]]


 Amplitude = 3.23464, mean = 15.14254, sigma = 0.26190 

 Gaussian Fit for Electron Beam Energy: 
 En = 3.23464exp(-(En-15.14254)^2) / (2*0.26190^2) 

 Gaussian Energy peak = 15.14254 

 Energy spread = 1.57142 
 rms Energy spread = 0.26190 

 Relative Energy spread = 0.10378 
 Relative rms Energy spread = 0.01730 
















[[HRRL_Emittance_Measurements_March14-18-2011]]