HE Calorimeter Upgrade Studies HE Calorimeter Upgrade Studies Proposing to replace HE scintillators with quartz plates for high luminosity LHC runs 1

“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,Turkey Cukurova U, Adana, Turkey ITU, Istanbul, Turkey METU,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 Studies Electron 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) Proton 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 and Submitted 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 Fibers We 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 Light Collection from Quartz Plates”, IEEE Transactions on Nuclear Science, Vol 55, Issue 2, , U. Akgun et al., "Quartz Plate Calorimeter as SLHC Upgrade to CMS Hadronic Endcap Calorimeters", XIII International Conference on Calorimetry in High Energy Physics, CALOR 2008, Pavio, Italy, May 2008, J.Phys.Conf.Ser.160:012015, Hadronic Energy Resolution

Quartz Plate Calorimeter with P-Terphenyl We 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 Super­LHC”, CALOR 2010, Beijing, China, 7 Hadronic Energy Resolution and Response Linearity

8 CMS Endcap Calorimeter (EE + HE). 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, , 2010 Quartz Plate Calo. with P-Terphenyl – EM mode Electromagnetic Energy Resolution and Response Linearity

9 Covering Quartz Plates with pTp and ZnO We evaporated PTP and RF sputtered ZnO over quartz plates

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, October P-Terphenyl Radiation Damage tested up to 40 MRad PTP (red) and ZnO (green) deposited quartz plate Produces 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 Fiber We 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 O 2. 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/cm 3 Liquid 0.97 g/cm 3 – Index: – Bright scintillator x2.3 of NaI; – emission between nm – Decay time: <30ns 16

Rig: Vacuum Tube Furnace – Anthracene “Double Boiler” 17 Nested pyrex tube double boiler – Molten anthracene shown -30cm tube furnace for 25cm Capillary fibers -Vacuum thermometer - Pyrex vacuum burette -Fibers placed vertically In 5 mm dia pyrex melt tube - At ~240°C, µ<0; Liquid Anthracene fountains from tops of fibers!

25 cm Anthracene Core Quartz Capillary Fibers 18 NA = 0.43 Core Diameters: µm

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.

The Glass Samples Produced Lead Vanadates doped with Iron (Fe2O3-PbO-V2O5) Lead Vanadates doped with Copper (CuO-PbO-V2O5) 20