Particle Transport Through AP2-Line and Debuncher

January 12, 2006 Particle transport through AP2-line and Debuncher

Valeri Lebedev

1. Particle yield from the target Production of negatively charged particles by the proton beam on the target was simulated by N. Mokhov using MARS for the proton beam momentum of 119.7 GeV/c and the horizontal and vertical rms beam sizes of 0.15 mm. Target is a disk 4.5" (11.43 cm) diameter, 3/8" height, made of inconel-600, with a corresponding displacement from the beam axis to provide the chord of 9.45 cm. Figure 1 presents distribution density, dN/d for major constituents of secondary beam current contained in 2.5% momentum spread, and Figure 2 presents corresponding total number dN N d pbar pbar

5 4 10 6 1 10 -(*0.01) -(*0.01) 5 3 10 K-(*0.1) K-(*0.1) Total  7 5 5 10 2 10

e(*0.01) 5 e(*0.01) 1 10 - 0 - 0 10 20 30 40 50 0  [mm mrad] 0 10 20 30 40 50  [mm mrad] Figure 1. Particle distribution density per one proton Figure 2. Total number of particles per one over transfer line acceptance for beta-function in the proton accepted into acceptance  obtained by target center of 3.45 cm and particles with 2.5% integration of Figure 1 data over . momentum window centered on 8.886 GeV/c. 20∙106 protons were used in simulations. 10 0.004 of particles contained in 4D ellipsoid described by the following equation: 0.003 2 2 x  y 2 2 1   x  y    , (1)  Ia j 0.002 where  is the beta-function in the target center. Icj As one can see - is the most populated 0.1 constituent of the beam. Their density 0.001 distribution is about 70 times larger than for 0 antiprotons. Density distribution far all hadrons 0 50 100 150 200 250 300 s [m] have similar shape while the electron density 0.01 Figure 3.0 Changes50 of total100 beam intensity150 contained200 in250 300 distribution is peaked at small . Number of sj muons is negligible at the target exit but they the acceptance =40 mm mrad and momentum spread 2.5% due to particle decays. Intensity is normalized on are produced in the line due to decays of pions. 1 proton encountered to the target. About 10% of pion decays result in muons

1 accepted to the line, so that muons carry about 10% of the total beam current at the line end. Figure 3 shows dependence of beam intensity change due to particle decays on distance traveled by the beam from the target. As one can see the decays lead to about 35% decrease in the beam intensity.

2. Particle Tracking Particle tracking through AP-2 and Debuncher has been carried out with all important details taken into account: non-linearity and scattering in the lithium lens, accurate treatment of chromatic effects and realistic aperture limitations. Figures 4-6 presents tracking results for present (end of 2005) machine state where both present optics and aperture limitations are taken into account. Figure 4 presents beam parameter changes for antiproton beam in the AP2 line. One can see that the largest beam loss of about 4 times happens in the “left bend” dipoles where particles are filtered out in momentum. Total antiproton production efficiency at the end of AP2 line is 3910-6, where we also took into Tue Jan 17 13:25:19 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.opt

2 4 . . 0 0 y t i P s / n P e d t n I 0 0 0 Intensity dP/P 290.051

Tue Jan 17 13:26:04 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.opt

0 4 1 0 . 0 ] m ] c [ m x c a [ e m c Y n & a t x t i a m m E X 0 0 0 Emit_X Emit_Y Xmax Ymax 290.051

Tue Jan 17 13:27:19 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.opt

0 0 1 1 ] ] m m c c [ [ X Y _ _ e e z z i i S S 0 0 0 Ax_bet Ay_bet Ax_disp Ay_disp 290.051 Figure 4. Results of particle tracking through AP2-line; rms proton beam size on the target - 212 m, beta-function at the target center - 3.4 cm corresponding to the lens gradient of 69.8 kG (peak lens current - 477 kA), AP2 optics is set to the end of 2005 optics. Dependences on the longitudinal coordinate for the beam intensity (relative units) and rms momentum spread (top), for maximum beam sizes and rms normalized emittances (middle), and for design beam envelopes (bottom). The bottom plot also shows aperture limitations used in the model.

2 account a factor of 0.82 related to antiproton absorption in the lithium lens[1]. Figure 5 shows similar picture for the first turn in Debuncher, where additional ~21% of antiprotons are lost with main aperture limitation set by the stochastic cooling pickups and the Schottky monitor in AP-10 straight line. As one can see the vertical emittance is decreasing faster meaning that the vertical aperture limitations are more pronouncing. Figure 6 presents beam intensity changes obtained by tracking for another 50 turns in Debuncher. The effect of bunch debunching was taken into account in the simulations. One can see that after turn 30 beam losses practically stop. That Wed Jan 18 11:43:54 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\Debuncher\ApertureUpgradeDec05\Deb_051122_Origi

5 1 1 0 . 0 y t i P s / n P e d t n I 5 1 7 0 . . 0 0 0 Intensity dP/P 505.326

Wed Jan 18 11:45:27 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\Debuncher\ApertureUpgradeDec05\Deb_051122_Origi

1 8 0 . 0 ] m ] c [ m x c a [ e m c Y n & a t x t i a m m E X 0 0 0 Emit_X Emit_Y Xmax Ymax 505.326

Wed Jan 18 11:50:33 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\Debuncher\ApertureUpgradeDec05\Deb_051122_Origi

8 8 ] ] m m c c [ [ X Y _ _ e e z z i i S S 0 0 0 Ax_bet Ay_bet Ax_disp Ay_disp 505.326 Figure 5. Results of particle tracking through the first turn in Debuncher. Beam parameters are obtained from AP-2 line tracking (see Figure 4). Debuncher optics is set to the optics measured at the end of 2005. Dependences on the longitudinal coordinate for the beam intensity and rms momentum spread (top), for maximum beam sizes and rms normalized emittances (middle), and for design beam envelopes (bottom). The bottom plot also shows aperture limitations used in the model.

Wed Jan 18 12:04:01 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\Debuncher\ApertureUpgradeDec05\Deb_051122_Origi -6 5 1 sets the total production efficiency to be about 2310 3 2 0 for acceptances h=28.5 mmmrad and h=24.5 6 2 0 . y 0 t mmmrad. The acceptances were computed from the i P s / n P e phase space coordinates of particles having largest d t n betatron amplitude. This result coincides with the I [1] 5

predictions of earlier less accurate simulations 7 . 0 0 which yield 24 mmmrad for lens gradient of 69.8 0 Intensity dP/P 50 kG/cm and 26.8 mmmrad acceptance (average of Figure 6. Dependence of beam intensity on turn actual horizontal and vertical acceptances), and one number for turns 2 to 52. Continuation of tracking additionally needs to decrease antiproton yield by 5% from Figure 5. due to larger beam size on the target - 212 m versus

3 120 m. Note that presently the real beam size is not accurately known and is estimated to be about 150x300 m. That drops expected production to about 20-2110-6. Similar to Figures 4-6 figures 7-9 present tracking results for optics upgrade (January 2006 optics for Debuncher and AP2) which includes changes in the aperture limitations (transverse Schottky monitors were removed) and in the optics change. Total antiproton production efficiency at the end of AP2 line is 4110-6. Losses at the first turn in Debuncher are about 18% and additional ~13% after 50 turns. The total production efficiency is about 3010-6 for acceptances h=40 mmmrad and h=36 mmmrad. Planned increase of extraction kicker aperture will yield other 6% improvements so that in this case the total production will be about 3210-6.

Figure 7. All as in Figure 4 but transfer line optics is corrected to the new (January 2006) optics.

4 Longitudinal distribution on AP-2 SEMs (OptiM simulations)

Thu Jan 05 14:41:53 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.opt

7 2 n o i c n u f . r t s i D 0 -300 Distribution over Px[mrad] at element 157 (isD:SM704) 300

5 Thu Jan 05 14:44:24 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.opt

5 2 n o i c n u f . r t s i D 0 -300 Distribution over Px[mrad] at element 430 (isD:SM723)300

5 2 n o i c n u f . r t s i D 0 -300 Distribution over Px[mrad] at element 556 (isD:SM733) 300 The pictures above show momentum distribution on SEMs

6 Transverse distributions on AP-2 SEMs (OptiM simulations and measurements)

0 C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\704-715 profiles from P58 file 13.dat * 32.000000 2 1 n o i c n u f . r t s i D 0 -9 Distribution over X[cm] at element 157 (isD:SM704) 9

0 C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\704-715 profiles from P58 file 13.dat * 12.000000 4 1 n o i c n u f . r t s i D 0 -9 Distribution over Y[cm] at element 157 (isD:SM704) 9

0 C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\704-715 profiles from P58 file 13.dat * 8.000000 8 n o i c n u f . r t s i D 0 -9 Distribution over X[cm] at element 186 (isD:SM706) 9

5 C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\704-715 profiles from P58 file 13.dat * 6.500000 6 n o i c n u f . r t s i D 0 -9 Distribution over Y[cm] at element 186 (isD:SM706) 9

7 C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\719-733 profiles from P58 file 15.dat * 0.800000 n o i c n u f . r t s i D 0 -9 Distribution over X[cm] at element 351 (isD:SM719) 9

0 1 . 1 0 ] m ] c [ m x c a [ e m c Y n & a t x t a i m m E X 0 0 0 Emit_X Emit_Y Xmax Ymax 290.051

0 0 1 1 ] ] m m c c [ [ X Y _ _ e e z z i i S S 0 0 0 Ax_bet Ay_bet Ax_disp Ay_disp 290.051

0 C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\SemTwiss.dat * 0.010000 1 0

1 C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\SemTwiss.dat * 0.010000 ] ] m [ m [ Y Y & & X X _ _ A P T S I E B D 3 0 - 0 BETA_X BETA_Y DISP_X DISP_Y 290.051

11 12 13 14 Tue Jan 10 17:29:13 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.opt Q701=-20 A

0 C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\704profilesQ701-702change.dat * 39.000000 8

1 Horizontal profiles for changes of Q701 n o

i SEM intensity was corrected c n u f

. to have the same sum of wire r t s i

D signals 0 3 - -5 Distribution over X[cm] at element 157 (isD:SM704) 5

Tue Jan 10 17:28:33 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.opt Q701=-10 A

0 C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\704profilesQ701-702change.dat * 42.000000 8 1 n o i c n u f . r t s i D 0 3 - -5 Distribution over X[cm] at element 157 (isD:SM704) 5

Tue Jan 10 17:27:34 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.opt Q701= 0 A

Tue Jan 10 17:14:38 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.opt +10 A

15 Tue Jan 10 17:12:48 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.opt +20 A

16 Simulation of Effect of Q701&702 changes on particle intensity distribution in AP2 line EmitX_N[cm] EmitY_N[cm] Xmax[cm] Ymax[cm] dP/P Intensity 0.00670952 0.0072542 1.829685 2.760216 0.0141853 0.006240 Nominal settings sigma=223 um 0.00642713 0.00761374 1.673445 2.788334 0.014154 0.006193 Nominal settings sigma=223 um 0.00670042 0.00740122 1.857877 2.835519 0.0141837 0.006336 Nominal settings sigma=223 um 0.00735036 0.0147395 1.585416 2.820509 0.0133538 0.004717 $iD:Q701 = 378.799438+20 0.00745899 0.0146309 1.672740 2.788057 0.0136062 0.004435 $iD:Q701 = 378.799438+20 0.00750294 0.0151282 1.536485 2.808407 0.0137707 0.004560 $iD:Q701 = 378.799438+20 0.00648639 0.00829403 1.820487 2.768747 0.0144188 0.006202 $iD:Q701 = 378.799438-20 0.00657977 0.00793411 1.870967 2.816550 0.014614 0.006253 $iD:Q701 = 378.799438-20 0.0067897 0.0081265 1.911801 2.801230 0.0141641 0.006111 $iD:Q701 = 378.799438-20 0.00895238 0.0118528 1.846859 2.752683 0.0146317 0.004699 $iD:Q701 = 378.799438-40 0.00968235 0.0105699 1.844129 2.785137 0.015042 0.004875 $iD:Q701 = 378.799438-40 0.00936568 0.00955417 1.847805 2.707957 0.0142087 0.004574 $iD:Q701 = 378.799438-40 0.00960451 0.0442856 1.740605 2.833230 0.0140114 0.002719 $iD:Q701 = 378.799438+40 0.0100347 0.0366724 1.535371 2.839148 0.0130319 0.002495 $iD:Q701 = 378.799438+40 0.00884829 0.0398886 1.515916 2.839638 0.0131283 0.002438 $iD:Q701 = 378.799438+40 0.00664929 0.00782999 1.769526 2.806371 0.0141079 0.006155 Nominal settings sigma=223 um 0.0069997 0.22335 1.597034 2.793144 0.0138639 0.001723 $iD:Q702 = 378.799438-40 0.00673598 0.0526644 1.596887 2.627623 0.0141045 0.003185 $iD:Q702 = 378.799438-20 0.00640741 0.0256413 1.951334 2.587177 0.013768 0.004270 $iD:Q702 = 378.799438+20 0.00686309 0.143707 1.814683 2.784778 0.0141406 0.002342 $iD:Q702 = 378.799438+40 Wed Jan 11 13:12:14 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.opt 7

$iD:Q701 = 378.799438+40 8 4 8 0 . 9 0 5 7 y . t i 0 P s / n P e t d n I 0 0 0 Intensity dP/P 290.051

Wed Jan 11 13:12:49 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.opt 7

$iD:Q701 = 378.799438+20 8 4 8 0 . 9 0 5 7 y . t i 0 P s / n P e t d n I 0 0 0 Intensity dP/P 290.051

Nominal 8 4 8 0 . 9 0 5 7 y . t i 0 P s / n P e t d n I 0 0 0 Intensity dP/P 290.051

17 Wed Jan 11 13:14:22 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.opt 7

$iD:Q701 = 378.799438-20 8 4 8 0 . 9 0 5 7 y . t i 0 P s / n P e t d n I 0 0 0 Intensity dP/P 290.051

$iD:Q701 = 378.799438-40 8 4 8 0 . 9 0 5 7 y . t i 0 P s / n P e t d n I 0 0 0 Intensity dP/P 290.051 1.2

-20 A 0.8 +20 A

-40 A 0.6

+40 A 0.4

0 0 50 100 150 200 250

Crosses mark BPM positions Wed Jan 11 16:17:47 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.opt

8 8 ] ] m m c c [ [ X Y _ _ e e z z i i S S 0 0 0 Ax_bet Ay_bet Ax_disp Ay_disp 290.051

18 Wed Jan 11 16:33:42 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.opt $iD:Q702 = 378.799438-40 7 8 4 8 0 . 9 0 5 7 y . t i 0 P s / n P e t d n I 0 0 0 Intensity dP/P 290.051

Wed Jan 11 16:34:18 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.opt $iD:Q702 = 378.799438-20 7 8 4 8 0 . 9 0 5 y 7 t . i 0 P s / n P e d t n I 0 0 0 Intensity dP/P 290.051

Wed Jan 11 16:34:42 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.opt

$iD:Q702 = 378.799438+20 7 8 4 8 0 . 9 0 5 7 y . t i 0 P s / n P e d t n I 0 0 0 Intensity dP/P 290.051

Wed Jan 11 16:35:01 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.opt

$iD:Q702 = 378.799438+40 7 8 4 8 0 . 9 0 5 7 y . t i 0 P s / n P e d t n I 0 0 0 Intensity dP/P 290.051

19 1.2

-20 A 0.8 +20 A

+40 A 0.4 -40 A

0 0 50 100 150 200 250

Effect of beam displacement on the target on SEM signal Thu Jan 12 18:21:59 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.opt nominal 0 2 1 ) 4 0 7 M S : D s i ( 7 5 1 . m e l e

t a . r t s i D 0 -6 X[cm] Y[cm] 6

Thu Jan 12 18:22:14 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.optThu Jan 12 18:22:29 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.opt x=+0.7 mm x=+1.4 mm 0 0 2 2 1 1 ) ) 4 4 0 0 7 7 M M S S : : D D s s i i ( ( 7 7 5 5 1 1 . . m m e e l l e e

t t a a . . r r t t s s i i D D 0 0 -6 X[cm] Y[cm] 6 -6 X[cm] Y[cm] 6

20 Thu Jan 12 18:23:06 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.optThu Jan 12 18:23:18 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.opt x= -0.7 mm x= -1.4 mm 0 0 2 2 1 1 ) ) 4 4 0 0 7 7 M M S S : : D D s s i i ( ( 7 7 5 5 1 1 . . m m e e l l e e

Horizontal displacement Thu Jan 12 18:33:36 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.optThu Jan 12 18:34:00 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.opt y= +0.7 mm y= +1.4 mm 0 0 2 2 1 1 ) ) 4 4 0 0 7 7 M M S S : : D D s s i i ( ( 7 7 5 5 1 1 . . m m e e l l e e

Thu Jan 12 18:34:18 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.optThu Jan 12 18:34:42 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.opt y= -0.7 mm y= -1.4 mm 0 0 2 2 1 1 ) ) 4 4 0 0 7 7 M M S S : : D D s s i i ( ( 7 7 5 5 1 1 . . m m e e l l e e

Vertical displacement EmitX_N[cm] EmitY_N[cm] Xmax[cm] Ymax[cm] dP/P Intensity 0.0260335 0.0153516 6.200632 8.370128 0.0893563 0.035207 Nominal 0.0340916 0.0254549 4.816475 9.301911 0.0906851 0.033642 x=0.7 mm 0.0611028 0.0549099 4.870492 12.869859 0.117622 0.030114 x=1.4 mm 0.0378825 0.0159712 6.350348 4.680031 0.116193 0.034282 x=-0.7 mm 0.0697514 0.0222862 7.014836 5.045234 0.154597 0.031884 x=-1.4 mm 21 0.0266841 0.0234183 6.152083 7.292717 0.0893971 0.027471 y=0.7 mm 0.0300442 0.0411718 6.990414 6.014521 0.0951646 0.011992 y=1.4 mm 0.027801 0.0235843 5.968269 6.855138 0.0910126 0.027193 y=-0.7 mm 0.0323792 0.0437042 5.841261 5.620299 0.0999975 0.012017 y=-1.4 mm

22 References

1. V. Lebedev, Production and collections of antiprotons, October 2001, http://www- bdnew.fnal.gov/pbar/organizationalchart/lebedev/Tevatron/RunIIB/PbarCollectRunIIbPresnt.pdf, http://www- bdnew.fnal.gov/pbar/organizationalchart/lebedev/Tevatron/BeamLines/ProdCollectAntiprot.doc

23 Fri Jan 13 14:53:53 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.opt

5 C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\TargetOffset\x_p07mm.dat[4]*1.000000 C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\TargetOffset\x_m07mm.dat[4]*-1.000000 C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\TargetOffset\x_p07mm.dat[4]*1.000000

] m c [ Y & X s e t a n i d r o o C 5 - 0 X Y 290.051

Fri Jan 13 14:54:09 2006 OptiM - MAIN: - C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\AP2.opt

5 C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\TargetOffset\y_p07mm.dat[5]*1.000000 C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\TargetOffset\y_m07mm.dat[5]*-1.000000 C:\VAL\Optics\Tevatron\TransferLines\AP2\Measurements\05Dec21\TargetOffset\y_p07mm.dat[5]*1.000000

] m c [ Y & X s e t a n i d r o o C 5 - 0 X Y 290.051