1
HE Calorimeter Upgrade Studies
Proposing to replace HE scintillators with quartz plates for high luminosity LHC runs
“HE UPGRADE PHASE II ISSUES”Yasar Onel
US-HE Upgrade Group:Iowa, Baylor, Fairfield, Fermilab, FIU, Maryland, Mississippi
Extended US Group for HCAL Upgrades:Boston, Minnesota, Princeton, Virginia, Notre Dame
International Group:Trieste, Italy
Bogazici U. Istanbul,TurkeyCukurova U, Adana, Turkey
ITU, Istanbul, TurkeyMETU,Ankara, Turkey
PREVIOUS QUARTZ PLATE WORK
A) As a baseline, replace the scintillator tiles in the original design of the hadronic endcap calorimeter (HE) with quartz plates. Quartz is proven to be radiation hard by the radiation damage tests with electron, proton, neutron and gamma beams.
B) As an addition to a) above, deposit on the quartz plates radiation-hard scintillator films. The films include pTerphenyl(pTP) and ZnO:Ga.
C) As a baseline, develop replaceable arrangements of wavelength shifting(WLS) fibers, which have been shown to collect efficiently the Cherenkov light generated in quartz plates. The configuration with high light yield is straight—through and amenable to periodic replacement.
D) Instead of c) above, develop rad-hard WLS fibers based on a quartz core, and using multicaldded films of rad-hard scintuillator/WLS, such as pTP or doped ZnO or doped CdS.
Quartz Radiation Damage StudiesElectron Irradiation Tests:Dumanoglu et al. “Radiation-hardness studies of high OH content quartz fibres irradiated with 500
MeV electrons” Nucl. Instr. Meth. A 490 (2002) 444-455Proton Irradiation Tests:Cankocak et al. “Radiation-hardness measurements of high OH content quartz fibres irradiated
with 24 GeV protons up to 1.25 Grad“ Nucl. Instr. and Meth. A 585 (2008) 20–27
Neutron and Gamma Irradiation Tests:U. Akgun et al. “Radiation Damage in Quartz Fibers Exposed to Energetic Neutrons” “Radiation Damage in Quartz Fibers Exposed to Energetic Neutrons” CMS Internal Note 2006/014 andSubmitted to IEEE Transactions on Nuclear Science.
4
5
Cherenkov Light Collection in Quartz• Good : Quartz is radiation hard.• Bad : We have to collect cerenkov photons. Very little light !! At fixed angle. • Strategy: Go deep in UV to collect Cerenkov photons.• We did R&D studies on
– WLS fiber geometry• Cerenkov light collection, uniformity, and efficiency
– Wrapping material reflectivity tests, Aluminum, Tyvek, HEM, Mylar.
Quartz Plate Calorimeter with WLS FibersWe built and tested 20 layers “WLS Fiber Embedded Quartz Plate Calorimeter Prototype”
F. Duru et al. “CMS Hadronic EndCap Calorimeter Upgrade Studies for SLHC - Cerenkov LightCollection from Quartz Plates” , IEEE Transactions on Nuclear Science, Vol 55, Issue 2, 734-740, 2008.
U. Akgun et al., "Quartz Plate Calorimeter as SLHC Upgrade to CMS Hadronic Endcap Calorimeters", XIIIInternational Conference on Calorimetry in High Energy Physics, CALOR 2008, Pavio, Italy, May 2008, J.Phys.Conf.Ser.160:012015, 2009
6
Hadronic Energy Resolution
Quartz Plate Calorimeter with P-TerphenylWe built and tested 20 layers “PTP Deposited Quartz Plate Calorimeter”
U. Akgun et al. "CMS Hadronic Calorimeter Upgrade Studies - P-Terphenyl Deposited Quartz Plate Calorimeter Prototype ", APS 2009, Denver, CO, USA, May 2009
B. Bilki et al. “CMS Hadron Endcap Calorimeter Upgrade Studies For Super LHC”, CALOR 2010, Beijing, China,
7Hadronic Energy Resolution and Response Linearity
8
We can use combination as radiation hard CMS Endcap Calorimeter (EE + HE).
U. Akgun et al. “CMS Hadronic Endcap Calorimeter Upgrade Studies for SLHC P-Terphenyl Deposited Quartz Plate Calorimeter Prototype'‘ IEEE Transactions on Nuclear Science, Volume 57, Issue 2, 754-759, 2010
Quartz Plate Calo. with P-Terphenyl – EM mode
Electromagnetic Energy Resolution and Response Linearity
Investigation of Radiation Hard Wavelength Shifters
We showed that radiation hard light enhancement tools (P-Terphenyl and Zinc Oxide) can be used with quartz.
U. Akgun et al., "P-Terphenyl Deposited Quartz Plate Calorimeter Prototype", IEEE Nuclear Science Symposium Conference, Dresden, Germany, 19-25 October 2008
10
P-Terphenyl Radiation Damage tested up to 40 MRad
PTP (red) and ZnO (green) deposited quartz plateProduces more light than plain quartz plate.
HE Upgrade Plans
We have two “viable” options for HE Upgrade, these can also be applied to EE region with 2 cm absorber thickness.
Will read signal from PTP deposited plate, directly. This will require radiation hard detector: Hamamatsu 7600 series, or
multi channel PMT The current technology of APD and SiPM is NOT enough.
Will use WLS fibers This requires rad-hard WLS fiber, which DOES not exist. We built a primitive prototype with PTP, it is promising. Need R&D on
PTP, ZnO deposition on quartz fibers. Sapphire fiber and quartz capilary filled by PTP and/or Anthracene is another option.
11
Radiation Hard WLS FiberWe Develop Radiation Hard Wavelength Shifing Fibers: Quartz
fibers with PTP/ZnO covered core.
12
We built a radiation hard WLS fiber prototype. Deposited pTp on the stripped region, on both face. Then the whole ribbon will be sandwiched between quartz plates.
Radiation Hard WLS Fiber
We prepared a “homemade” rad-hard WLS fiber. We stripped the plastic cladding from QP fibers for “middle 20 cm” portion of 60 cm fibers.This unit was tested with 80 GeV electron shower. The red line show the pedestal. With a very simple prototype we collected substantial signal.
We try to optimize the model using Geant4 simulations.13
Anthracene (+ other PAH) Quartz Capillary Scintillating/WLS Solid Fibers
• Fairfield*–Iowa–Mississippi Forward Collaboration
Scintillating and WLS Fibers• Collaboration Continuing Goals:
– HE upgrades: Scintillating Film Quartz Plates– Forward E-M calorimeter – New Glasses; SE Cal– Forward Lepton-Photon – SE Cal
14
Anthracene (+ other PAH) Quartz Capillary Scintillating/WLS Solid Fibers
• The Idea: Under vacuum, fill quartz capillaries with molten PAH organic scintillators/WLS with good Raddam Resistance to form optical waveguides.
• The confining and impervious Q-capillary: a) forces the frozen solid core to a continuous amorphous but nearly ordered fiber; b) keeps G negative for the reverse reaction after radiolysis, and c) prevents interactions with O2. • Follows pioneering work by R.Ruchti et al. with liquid cores.
15
Anthracene Properties• Anthracene
– Vibrational energy dissipation• Reduces raddam
– Melts: 218°C Boils: 340°C; soluble methanol– Densities: Solid 1.25 g/cm3 Liquid 0.97 g/cm3 – Index: 1.595– Bright scintillator x2.3 of NaI; – emission between 350-500nm– Decay time: <30ns
16
Rig: Vacuum Tube Furnace – Anthracene “Double Boiler”
17
Nested pyrex tube double boiler – Molten anthracene shown
-30cm tube furnace for 25cmCapillary fibers
-Vacuum thermometer
- Pyrex vacuum burette
-Fibers placed verticallyIn 5 mm dia pyrex melt tube
- At ~240°C, µ<0; LiquidAnthracene fountainsfrom tops of fibers!
Preliminary: Anthracene core 25 cm fibers
19
7 fibers pumped by Hg UV Pen Source,With one fiber bent up to camera
Fibers bent toward camera
Fibers cores: 250 µm–750 µm
Sensitive to 137Cs at far end.
Quant. Measurements TBD.