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HPS Beamline:Background Rates, Sensitivity to Field Uncertainties
M. Ungaro HPS Collaboration Meeting, JLAB, May 2011
1. Concrete Wall thickness Study2. Dose on Electronic Rack Beam Left3. Dose on ECAL4. Estimate Sensitivity to Field Uncertainties
HPS Collaboration Meeting, JLAB, May 2011 2
HPS Setup
Frasc. Magn. 1
Pair Spect
Frasc. Magn. 2
M. Ungaro
HPS Collaboration Meeting, JLAB, May 2011 3
CLAS12 – CLAS6 – HPS Centers
M. Ungaro
191.6cm
CLAS12
CLAS6 CLAS12HPS TEST
191.6cm1195.6cm
HPS Collaboration Meeting, JLAB, May 2011 4
CLAS12 – CLAS6 – HPS Centers
M. Ungaro
CLAS6 CLAS12HPS TEST
191.6cm1195.6cm
“CLAS6”
HPS Collaboration Meeting, JLAB, May 2011 5
CLAS12 – CLAS6 – HPS Centers
M. Ungaro
1195.6cm
“CLAS6”
CLAS6 CLAS12HPS TEST
191.6cm1195.6cm
HPS Collaboration Meeting, JLAB, May 2011 6
CLAS12 – CLAS6 – HPS Centers
M. Ungaro
HPS
CLAS6 CLAS12HPS TEST
191.6cm1195.6cm
HPS Collaboration Meeting, JLAB, May 2011 7
HPS Test Magnets Field MapsProvided by Stepan, CLAS Note 2011-2Measurements of Frascati, PS Magnets
Frascati Magnets Current for 0.25 Tm:335.9 A (based on max field value)
Pair Spectrometer Field: 0.5 T field
Frascati Magnet MeasurementZ (cm)
x (c
m)
Field (Gauss)
M. Ungaro
HPS Collaboration Meeting, JLAB, May 2011 8
HPS Test Chicane Alignment
2.2 GeV Electron (cyan) Zoomed in
M. Ungaro
2cm radius “bulls eye” tubesLocated 10m and 20m fromPS magnet
2.2 GeV electron (cyan)
Red Dot = hit
PS at 0.5T
Frascati Magnet at 1/0.8316 Or 120.3%
HPS Collaboration Meeting, JLAB, May 2011 9
HPS Test Beamline Flange
Vacuum Flange at Exit of 2nd Dipole
2 cm Stainless Steel.Heigth: 3.1’’
No Effect if we use Aluminum
Holes Separation: 157.0 mmID: 2’’
Kapton Window 100 mm
M. Ungaro
HPS Collaboration Meeting, JLAB, May 2011 10
HPS Test Beamline
150’’ Helium BagD=2’’
200’’ Steel PipeID = 2’’OD = 3’’
Photon Absorber:30cmx40cmx50xcm W
M. Ungaro
HPS Collaboration Meeting, JLAB, May 2011 11M. Ungaro
HPS Beamline Wall
Electronic Rack
Lead Shields
Concrete Wall(10cm)
HPS Collaboration Meeting, JLAB, May 2011 12M. Ungaro
HPS Beamline Wall
Electronic Rack
Lead Shields
Concrete Wall(50cm)
HPS Collaboration Meeting, JLAB, May 2011 13M. Ungaro
HPS Beamline Wall Thickness Study
Doses in all EC
eg1 dvs ------ particle GeV/s GeV/(s cm2) nrad/s nrad/(scm2) rad/year
pi- 1191 0.0280856 0.954882 2.25045e-05 0.0301131 e- 472301 11.1311 378.446 0.00891916 11.9347 gamma 2390098 56.3294 1915.14 0.0451358 60.3959 n 28118 0.662701 22.5312 0.000531011 0.710543 e+ 280506 6.61094 224.765 0.00529723 7.08819 pi+ 1536 0.0362203 1.23145 2.90227e-05 0.0388351
hps_test_shield WALL = 10cm ------ particle GeV/s GeV/(s cm2) nrad/s nrad/(scm2) rad/year
pi- 340 0.00803177 0.273072 6.43571e-06 0.00861159 e- 634268 14.9483 508.228 0.0119778 16.0275 gamma 5006186 117.985 4011.37 0.0945392 126.502 n 19218 0.452949 15.3998 0.00036294 0.485648 e+ 337722 7.95938 270.611 0.00637771 8.53398 pi+ 271 0.00639646 0.217473 5.12537e-06 0.00685823
HPS Collaboration Meeting, JLAB, May 2011 14M. Ungaro
HPS Beamline Wall Thickness Study
Doses in all EC
configuration GeV/s GeV/(s cm2) nrad/s nrad/(scm2) rad/year
eg1_dvs 3180378 74.9546 2548.38 0.0600598 80.3657 WALL 10cm 6313807 148.803 5059.14 0.119233 159.545 WALL 20cm 6055976 142.726 4852.55 0.114364 153.03 WALL 30cm 6001375 141.439 4808.79 0.113333 151.65 WALL 40cm 5455224 128.568 4371.17 0.103019 137.849 WALL 50cm 5072764 119.554 4064.72 0.0957965 128.185
Getting Closer, but more work to do…
HPS Collaboration Meeting, JLAB, May 2011 15M. Ungaro
HPS Electronic Rack Study
Rates (MHz)
4meters x 4 metersZ at targetX = 3meters
HPS Collaboration Meeting, JLAB, May 2011 16M. Ungaro
HPS Electronic Rack Study
Background Flux Density (normalized to 1)
mm
4meters x 4 metersZ at targetX = 3meters
HPS Collaboration Meeting, JLAB, May 2011 17M. Ungaro
HPS Electronic Rack Study
Fluences, Assuming all Energy is Deposited in the Electronic Rack
hps_test_shield5 ------ particle GeV/s GeV/(s cm2) nrad/s nrad/(scm2) rad/year
pi- 0 0 0 0 0 e- 67295 1.58601 53.9229 0.00127085 1.70051 gamma 328263 7.73646 263.032 0.00619909 8.29497 n 16788 0.395668 13.4523 0.000317042 0.424232 e+ 15980 0.376626 12.8049 0.000301784 0.403815 pi+ 0 0 0 0 0TOTAL: 434570 10.2419 348.213 0.00820663 10.9813
RADIATION DAMAGE IN DETECTORS AND ELECTRONICS:Usually 5000 rad in minutes. We’re ok, even considering Neutron-equivalent damage for silicon chips.
Vasilescu and G. Lindstroem, Displacement damage in silicon, on-line compilation.RADIATION DAMAGE IN DETECTORS AND ELECTRONICS Ronald Lipton, Fermilab, Batavia, IL 60510, U.S.A.
HPS Collaboration Meeting, JLAB, May 2011 18M. Ungaro
ECAL Rates
IC Calorimeter, eg1-dvcs ECAL, HPS Test
HPS Collaboration Meeting, JLAB, May 2011 19M. Ungaro
ECAL Background Origin
IC Calorimeter, eg1-dvcs ECAL, HPS Test
Mostly from target Mostly Vac Box (scattered e-)
HPS Collaboration Meeting, JLAB, May 2011 20M. Ungaro
ECAL Dose
ECAL, HPS Test
IC Calorimeter, eg1-dvcs
eg1_dvcs ------ particle GeV/s GeV/(s cm2) nrad/s nrad/(scm2) rad/year
pi- 103 0.139382 13.4819 0.0181305 0.425164 e- 18511 24.895 2408 3.2383 75.9386 gamma 375131 504.48 48796.5 65.6219 1538.85 n 4223 5.67924 549.331 0.738745 17.3237 e+ 15530 20.886 2020.23 2.71682 63.7098 pi+ 58 0.0787799 7.62008 0.0102476 0.240307 TOTAL 410876 552.55 53446 71.8747 1685.47
hps_test_shield5 ------ particle GeV/s GeV/(s cm2) nrad/s nrad/(scm2) rad/year
pi- 0 0 0 0 0 e- 7473 10.0498 972.077 1.30726 30.6554 gamma 86754 116.668 11284.8 15.176 355.879 n 451 0.607414 58.7528 0.0790114 1.85283 e+ 5997 8.06546 780.141 1.04914 24.6025 pi+ 0 0 0 0 0 TOTAL 100813 135.575 13113.7 17.6354 413.553
HPS Collaboration Meeting, JLAB, May 2011 21M. Ungaro
Field Knowledge Sensitivity
HPS Collaboration Meeting, JLAB, May 2011 22M. Ungaro
Field Knowledge Sensitivity
https://userweb.jlab.org/~ungaro/maureepage/proj/HPS/field_variations/field_variations.html
Example: at ECAL entrance:
Electron Beam: 1 mm/Frascati %Electron Beam: 0.6mm/PS %Photon Beam: 1.1mm/Frascati %Photon Beam: 0.1mm/PS%
HPS Collaboration Meeting, JLAB, May 2011 23M. Ungaro
Summary
1. Background sources are identified2. Increasing wall thickness from 10cm to 50cm only gives us
20-25% gain3. More work to be done to optimize beamline4. Radiation doses on EC is well below eg1-dvcs levels5. Radiation damage to Electronic Racks is negligible6. Electrons: ~0.5-1mm sensitivity / PS, Frascati%7. Photons: ~0.1-1.1mm sensitivity / PS, Frascati%