1. SIDDHARTA - Status Report
SIlicon Drift Detector for Hadronic Atom
Research by Timing Applications
SIDDHARTA - Status Report
Johann Zmeskal Stefan-Meyer-Institut für subatomare Physik, Wien
LNF- INFN, Frascati, Italy
Stefan-Meyer-Institut, Vienna, Austria
Politecnico, Milano, Italy
MPE, Garching, Germany
IFIN – HH, Bucharest, Romania
Univ. Victoria, Canada
RIKEN, Wako-shi, Japan
Univ. of Tokyo, Japan
37th LNF Scientific Committee
December 1, 2008

2. Content Installation of the SIDDHARTA setup Degrader optimization
First results of gaseous kaonic helium
SIDDHARTA Programme
Beam Time Request
37th LNF Scientific Committee

3. Installation of the SIDDHARTA setup
Aug. 15 – 30: preparation for and
movement to DANE
Sept. 1 – 15: vacuum and cryogenic tests
debugging
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4. SIDDHARTA Setup Turbo molecular pump Target cooling system
Varian, 150 l/s
Target cooling system
APD-cooler 8 20 K
SDD cooling system
Pulse Tube cooler K
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5. Cryogenic target cell Working T 22 K Working P 2.5 bar Alu-grid
Side wall:
Kapton 50 µm
Kaon entrance
Window:
Kapton 50 µm
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6. SDD – Silicon Drift Detector
unit for 2 CDD-chips
6 cm2 active area
SDD window frame
(pure Al %)
cooling
back-plane
flexible Kapton
boards
pre-amplifier
board
HV+LV distribution
board
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7. 37th LNF Scientific Committee

8. SIDDHARTA setup moved
to DANE

9. SIDDHARTA interaction region
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10. Installation of SDD detector
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11. Cryogenic target and SDD detector
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12. Installation finished, ready for testing
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13. SIDDHARTA debugging phase
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14. Problems to be solved Latch-up of SDDs
due to high background mainly during injection
(checked to be MHz on 1 SDD…..)
Installation of shielding
Adapting SDD electronics for “fast recovery”
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15. Shielding of SIDDHARTA setup
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16. Lead shielding of SIDDHARTA
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20. SIDDHARTA X-ray calibration
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22. X-ray calibration spectrum
counts / 40 eV
energy [eV]
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23. SIDDHARTA Kaonic helium
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24. background about 10 x K-H DEAR  but, we have the “kaon-trigger” !!!
K-He spectrum – I.L. ~ 15 pb-1
background about 10 x K-H DEAR
 but, we have the “kaon-trigger” !!!
x102
events / 50eV
energy [eV]
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25. without trigger K-He with trigger Au L-lines L L L Lhigher
events / 50eV
Au L-lines
K-He with trigger
events / 50eV
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Coincidence region
Counts/3 channels
time
Time difference
Kaon trigger + coincidence region
Lalpha
Lgamma
Lbeta
Counts/30 eV
energy [eV]
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X-ray energy [eV]
Counts/30 eV
Lalpha
Lgamma
Lbeta
coincidence region
Non-coincidence region
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28. Degrader studies - optimization
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29. Measurements started on November 6, and 5 different degrader were used
optimal degrader thickness found
window of safe operations
(+/- 50 microns around optimal degrader,
about 2% of total material budget)
350 microns less than optimal degrader
 K-Al X-rays seen (solid targets?)
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30. Time correlation kaon –X-ray signal
Degrader III
coincidence window
~ 1.2 µs
counts per channel (1ch=8.3ns)
time
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31. Coincidence window: 1.2 µs
Degrader II
Coincidence window: 1.2 µs
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32. Coincidence window: 1.2 µs
Degrader III
Coincidence window: 1.2 µs
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33. Coincidence window: 1.2 µs
Degrader IV
Coincidence window: 1.2 µs
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34. Degrader optimization
K-He(L)
S/B ratio
I.L. [pb-1]
K-He/pb-1
Deg 2
397±24
4.0
11.4
34.8±2.1
Deg 3
590±30
4.6
14.8
39.9±2.0
Deg 4
420±24
4.2
11.1
37.8±2.2
Deg 5
209±19
2.6
9.0
23.2±2.1
Degrader base
made of Mylar:
-60,-40 mm µm
-40,-20 mm µm
-20, mm µm
0,+20 mm µm
+20,+40 mm µm
+40,+60 mm µm
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35. Best degrader -350µm: K-Al Coincidence window: 1.2 µs
7-6
8-7
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36. Kaonic helium
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37. very preliminary SIDDHARTA K-He 3d2p L yield = (12 ± 4)% 6d2p 4d2p
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39. KEK: E570 K-He
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40. TRIUMF Headline Story:
Awards & Honours: The 2008 Nishina Memorial Prize
Ryu Hayano
Member of SIDDHARTA collaboration
KEK: Kaonic Helium
CERN-AD: Antiprotonic Helium
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41. SIDDHARTA programme
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42. using K-He measurement
K-H S/B extrapolation
using K-He measurement
K yield of K-H is a factor less than the
K-He L  yield and the K-H width is a factor 1.5 bigger
S/B for K-H will be 1/ 2.5
1/5
S/B = 1/3 -> precision: 6 eV
S/B = 1/5 -> precision: 8 eV
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43. Expected SIDDHARTA result
Kaonic hydrogen precision estimated using the kaonic
helium measurement
error in shift: better than  10 eV
error in width: better than  35 eV
-500
500
200
400
600
800
1000
shift e1s [eV]
Davies et al, 1979
Izycki et al, 1980
Bird et al, 1983
SIDDHARTA
KpX
width G1s [eV]
DEAR
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44. Plans for December 2008 Measurement of K-He until mid of December
-> data for publication
(yield and position of L-lines)
Collimator test for kaon monitor: expected background reduction by a factor of ~2
a first test with hydrogen might be possible
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45. Kaon detector collimator
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46. Dedicated SIDDHARTA Run 2009 beam time request
Stable, dedicated working conditions
Better electron injection (background)
Optimization of the duty-cycle  integrated luminosity
Precision measurement of kaonic hydrogen pb-1
(with 10 pb-1/day and 70 % duty-cycle: days)
Measurement of kaonic deuterium pb-1
(first measurement: might need new shielding)
Further options/experiments are under evaluation
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47. We wish to express our THANKS TO Director LNF, Mario Calvetti
DANE machine staff
G.Corradi, D. Tagnani
(Electronics)
B. Dulach, C. Capoccia
(Mech. Design, Installation)
Staff of the mechanical workshop
(M.A. Franceschi, G. Bisogni)
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