HPS Beamline: Background Rates, Sensitivity to Field Uncertainties M. Ungaro1HPS Collaboration Meeting, JLAB, May 2011 1.Concrete Wall thickness Study

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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


CLAS12 – CLAS6 – HPS Centers

M. Ungaro

191.6cm

CLAS12

CLAS6 CLAS12HPS TEST

191.6cm1195.6cm



M. Ungaro


191.6cm1195.6cm

“CLAS6”



M. Ungaro

1195.6cm

“CLAS6”


191.6cm1195.6cm



M. Ungaro

HPS


191.6cm1195.6cm


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 Test Chicane Alignment

2.2 GeV Electron (cyan) Zoomed in

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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 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

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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 Beamline Wall

Electronic Rack

Lead Shields

Concrete Wall(50cm)


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 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 Electronic Rack Study

Rates (MHz)

4meters x 4 metersZ at targetX = 3meters



Background Flux Density (normalized to 1)

mm

4meters x 4 metersZ at targetX = 3meters



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.


ECAL Rates

IC Calorimeter, eg1-dvcs ECAL, HPS Test


ECAL Background Origin

IC Calorimeter, eg1-dvcs ECAL, HPS Test

Mostly from target Mostly Vac Box (scattered e-)


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


Field Knowledge Sensitivity


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%


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%

Documents

HPS Beamline: Background Rates, Sensitivity to Field Uncertainties M. Ungaro1HPS Collaboration Meeting, JLAB, May 2011 1.Concrete Wall thickness Study